:

VKI - Patricia Corieri – Philippe Léonard – Michel Riethmuller – Mario Carbonaro

CIRA – Marika Belardo

INCAS – Claudia Dobre

DLR – Tania Kirmse – Judith Kokavecz

Uleic: Frankie McKeon, Maarten Tas

REStARTS –The Experiments

2

I. How does a plane fly? ................................................................................................ 4

0. Flying planes and other Flying Objects ........................................................................................ 4

Preliminary experiment: Flying Planes and other Flying Objects ....................................................... 4

1. Concept of forces .......................................................................................................................... 6

Session 1: How do I understand forces? .......................................................................................... 6 Session 2: Let‟s experience forces ................................................................................................... 8 Session 3: Measure a force ............................................................................................................ 11 Session 4: Balance of forces – Velocity = 0 .................................................................................... 14

2. Concept of Pressure .................................................................................................................... 16

Session 1: „Fakir bed‟ or the pressure applied on a solid ................................................................ 16 Session 2: Pressure /solid-liquid-gas .............................................................................................. 18 Session 3: Pressure and Height – Experiment 1 ............................................................................. 20 Session 4: Pressure and Height – Experiment 2 ............................................................................. 22 Session 5: Pressure and Density.................................................................................................... 24 Session 6 (optional): Pressure of the air if you have a large height difference ................................. 26

3. Concept of Gravity Force ............................................................................................................ 28

Session 1: Experiments on gravity concept 1 ................................................................................. 28 Session 2: Experiments on gravity concept 2 ................................................................................. 30 Session 3: Challenge : How to create a opposite force to gravity .................................................... 32 Session 4: Find the gravity center of an object ............................................................................... 34

4. Concept of Lift Force ................................................................................................................... 36

Session 1: Preparation for the concept of lift................................................................................... 36 Session 2: Lift of the airfoil of the airplane ...................................................................................... 39 Session 3: Bernoulli bag, another surprising application of the Bernoulli theorem ........................... 41

5. Concept of Friction Force ............................................................................................................ 42

Session 1: Feel the friction force .................................................................................................... 42 Session 2: How can we change the friction force – Step 1 Challenge and conception of the experiments ................................................................................................................................... 44 Session 3: How can we change the friction force – Step 2 Scientific approach ................................ 46 Session 4: Demonstrative experiments with the small wind tunnel .................................................. 48

6. Concept of Thrust Force.............................................................................................................. 49

Session 1: Thrust and aircraft motor ............................................................................................... 49

7. Concept of Balanced Forces and Gravity Center ....................................................................... 50

Session 1: Find the gravity center of an object ............................................................................... 50 Session 2: Displacement of a plane in the three dimension space .................................................. 52 Session 3: Paper planes and direction ........................................................................................... 53

II. Greening Air Transport ........................................................................................... 56

1. Noise ............................................................................................................................................ 56

Session 1: Sound generation ......................................................................................................... 56 Session 3: Sound visualisation ....................................................................................................... 60 Session 4: Sound level measurement ............................................................................................ 65

REStARTS –The Experiments

3

Session 5: Sound source detection ................................................................................................ 70 Session 6: Noise reduction............................................................................................................. 73 Session 7: Measuring the noise level and the noise spectrum of a noise generator (speaker ) ........ 77

2. Drag .............................................................................................................................................. 80

Session 1: Demonstrating that drag is influenced by the shape of the object .................................. 80 Session 2: Demonstrating that drag is influenced by the viscosity of the fluid .................................. 82 Session 3: Demonstrating that drag is influenced by the smoothness or roughness of the surface .. 84 Session 4: Measuring the drag of different forms, different degrees of roughness and at different wind speed .................................................................................................................................... 86

3. Turbulence ................................................................................................................................... 89

Session 1: Illustrate laminar and turbulent flow in a very simple way ............................................... 89 Session 2: Illustrate turbulent flow using ink ................................................................................... 92 Session 3: Illustrate turbulent flow using a smoke generator ........................................................... 93

III. How a plane can fly assuring safety ? .................................................................. 98

1. What is Safety in Air Transportation ? ........................................................................................ 98

Session 1: What is Safety in Air Transportation ? ........................................................................... 98 Session 2: Active Safety in the Air Transportation .......................................................................... 99 Session 3: Passive Safety in Air Transportation............................................................................ 101

2. Which Materials for a Transport Airplane ? .............................................................................. 103

Session 1: Materials for a Transport Airplane ? ............................................................................ 103 Session 2: Which Forces Act on a Flying Airplane? Airplane parts and loads................................ 106 Session 3: How Design Safe Aeronautical Structures? Which maximum load can an aeronautical structure withstand to? ................................................................................................................. 108

3. Flight at high altitude ................................................................................................................. 109

Session 1: Flight at high altitude ................................................................................................... 109 Session 2: How works a pressurized fuselage .............................................................................. 110 Session 3: Ice Problems .............................................................................................................. 113

4. Critical situation in take off or landing phase........................................................................... 116

Session 1: Critical situation in take off or landing phase................................................................ 116 Session 2: One Engine Out Condition .......................................................................................... 118 Session 3: Side Wind Condition ................................................................................................... 120 Session 4: Crashworthiness ......................................................................................................... 123

REStARTS –The Experiments

4

Objective 1: Introduce that all the experiments that will be performed during the following week are linked

with the concept of flying.

Objective 2: Flying: what is the meaning of this verb?

Objective 3: What is specific to a plane when it is flying as compared to a bird, a balloon, a helicopter,

and other flying objects

E x p l a n a t i o n :

This preliminary experiment will prepare the pupils for studying the flight of airplanes. The first question

they should test is “how does a plane fly?”

Finally, what is flying?

Are there several ways of flying?

Is there a difference between flying and falling?

All these questions are also related to the history of flight.

The pupils will get an understanding of what flying is (and what it is not) and decisions can be made what

kind of flying will be treated in this topic.

M a t e r i a l :

Use all your imagination and give all the materials that can be used to build a flying object:

Ping-pong ball

Hair dryer

Feather

Paper

Straw

Balloon

Light plastic bags

….

Pictures of planes, shuttle, birds, helicopter, balloon, car, buses, insects, glider, parachute ….

REStARTS –The Experiments

5

M a x i m u m d u r a t i o n :

45 minutes

M a i n q u e s t i o n s t o b e a s k e d :

What is flying?

Is an airplane flying?

Is a falling stone flying?

Is a parachute flying?

M a i n a c t i v i t i e s

Give these objects to the pupils working alone or in groups and ask them to build a flying object or you

can also ask them first to draw a flying object before building it.

Test phase: you can stay in class to fly the object, but they will always prefer to drop it in a stair case.

Discuss with the pupils which of these objects fly and which do not fly. Ask them, what is special about of

the flight of an airplane.

Prepare with them a big poster on the assumptions of what is flying. During all the module of aeronautics

experiments you can come back to this poster and refine the concept with them and with their new

discoveries.

REStARTS –The Experiments

6

Before you start the investigation on the concept of force, this session will help you to access the mental

representation that students have about forces.

For young french speaking children, force and strength, is the same word. This induces already a very

“directed” representation!

O b j e c t i v e s

To design experiments to show what a force is.

To discuss and show which are the effects of forces.

M a t e r i a l

All kind of objects, for example:

heavy weights

cars with wheels

hair dryer

straw

ping pong ball

heavier ball

ropes

box with water

small airplanes

light plastic bags

M a i n q u e s t i o n s t o b e a s k e d

What do you think a force is?

How do you know a force is present?

Which forces do you think are needed for a plane to fly?

How can you find out?

I n t r o d u c t i o n / S t a r t e r s

The teacher shows a picture or a movie of a flying plane and says that all together they are going to

spend some lessons to understand how a plane is able to fly and all the physics related to this.

However, before explaining this, they will experiment with several concepts of forces, pressure, gravity …

REStARTS –The Experiments

7

M a i n a c t i v i t i e s

Propose to the pupils to form groups of 2

Ask them to choose objects and to use them to illustrate their concept of forces

Propose to the pupils to form groups of 2

Ask them to choose objects and to use them to illustrate their concept of forces

Each group comes in front of the classroom to illustrate its concept of force. They can choose

either to explain or to mime their understanding of force.

Their example will demonstrate that forces can be very different (pushing, pulling, rolling …)

C o n c l u s i o n / P l e n a r y

Forces will be associated by pupils to their effect: pushing, pulling, falling, flying, rolling …

REStARTS –The Experiments

8

At this age, primary school, we want that the pupils experience with their

bodies that the effect of forces are directional, vary in intensity (and are

applied at one point).

Objective 1: Experience the impact of forces using different angles

Objective 2: Explain that forces can be applied in different direction

M a t e r i a l

3 strong ropes And/or 3 fitness elastics

heavy bucket (15 kg of sand for example)

chalk

compass

et square

Gloves (for pulling ropes)

M a i n q u e s t i o n s t o b e a s k e d :

Do you think that force has a direction?

I n t r o d u c t i o n / S t a r t e r s

Give your students a rope and then ask them to organise themselves and to pull.

Discuss with them what happened?

Do the same with 3 groups and three ropes attached in the middle. What is the difference?

M a i n a c t i v i t i e s

Optional mathematical experiments: how to attach 3 ropes around a

bucket at different angles?

Some ideas for experiments are explained below, but you may have

other ideas:

The concept of angle has not been introduced in the curriculum for your group.

For 120º, you take the perimeter of the bucket with a rope, you divide it in three and divide the rope in

three equal parts or possibly you ask them to find a way of dividing three parts.

REStARTS –The Experiments

9

For 180º and two times 90º degrees you can again use a rope

passing by the centre of the bucket and then take a set square to

adjust a right angle.

The concept of angle is known:

There are plenty of ways to do this. One of them consists in drawing

on the floor, dividing the angle like a piece of cake… It can be

checked with a rope like the experiments for the younger children…

Please feel free concerning the time you want to dedicate to this parallel

activity and to treat the mathematical aspects up to the point you want to

reach with your students. We propose some starting ideas, but there are

plenty of alternatives that you might enjoy testing with your class.

C o n c l u s i o n / P l e n a r y

Snowball: ask pupils to write down one thing they learnt about forces

(give them 30 seconds), then ask pupils to form pairs and write down

three things they have learnt about forces (give them 1 minute), then

ask the pupils to sit in groups of four and let them write six things they

have learnt about forces (give them 2 minutes). Each group of four

feeds things back to the rest of the class.

Please feel free concerning the time you want to dedicate to this parallel activity and to treat the

mathematical aspects up to the point you want to reach with your students. We propose some starting

ideas, but there are plenty of alternatives that you might enjoy testing with your class.

Divide the students in three groups.Mount the bucket with the 3 ropes attached at an angle of

120º. Then ask them to pull the rope and find a way to stabilise the bucket. Ask them to draw

their representation of the forces on the floor with the chalk.

Do the same but with the two ropes forming an angle of 180º, and the last one forming 90º. Ask

them to draw their representation of the forces on the floor with the chalk, in a different colour.

Do the same, but now each of the groups are placed next to each other. Ask them to draw their

representation of the forces on the floor with the chalk, in a different color. Discuss with them their

conclusions.

REStARTS –The Experiments

10

Put one student pulling two of the ropes, then all the other students at one end.

Apply the same procedure as for the pictures below

Discuss the difference with the students

REStARTS –The Experiments

11

Objective 1: Introduce the quantification of a force

Objective 2: Relate experimentally Force and Mass

E x p l a n a t i o n

After their qualitative experiments on forces we will start quantitative experiments by measuring some

forces.

M a t e r i a l

Scales

Dynamometers of several ranges

Objects of different weight

Empty bag to fill with objects

M a x i m u m d u r a t i o n

90‟

M a i n q u e s t i o n s t o b e a s k e d

What do you think a force is? How do you know a force is present?

How much weight can you lift? How can you measure a force?

What is the difference between Mass and Force?

I n t r o d u c t i o n / S t a r t e r s

Ask to the children if they can imagine the forces they have applied on the ropes during the session 2 of

experiments.

This question is possibly a bit too complex for them, at this stage the objective is just to listen their

explanations and their representation.

Then ask them the weight they are able to lift.

Then you can relate both forces: traction on the rope and lift of a heavy weight. (Show a picture of this

set-up).

The main activity will be to measure the forces.

M a i n a c t i v i t i e s

The empty bag will be filled successively with several objects of different weight;

REStARTS –The Experiments

12

Give to each group a scale and ask the children to measure the weight of the bags containing the

objects;

Then ask each of them to measure the heaviest weight they can lift.

Referring to session 2 of experiments where they pulled the rope, ask your students if they can

imagine how the pulling forces can be measured.

You will then distribute the dynamometer, and they will measure the weight of the same objects

already weighted with the scale on part A

Dynameters are usually graduated in Newtons. Ask them to compute the ratio between the

weight measured on the scale and the force measured with the dynamometer. The objective is to

show evidence of the factor between Mass (kg) and Force (Newton). This factor is a constant

(gravity).

Optional: mathematical extension, you can also report the results of this last experiment on a

graphical display.

Attach a rope on a wall or something very solid, and attach to it the dynamometer corresponding

to the range of force of the heaviest weight that children can lift.

Ask them to pull and to measure the force they apply while pulling

Do exactly the same experiment, attaching the elastic rope now, and the dynamometer. Then ask

the students to apply several forces on the elastic rope.

Students will measure the extension of the elastic ropes as a function of the force applied and

measure it on the dynamometer

If they are sufficiently advanced ask your students to represent their results on a graph

You can use your elastic rope as a new instrument to measure forces

The same can be done with small elastic bands, for smaller forces

C o n c l u s i o n / P l e n a r y The students approach the way of measuring/quantifying a force.

These experiments have put in relation the quantification of the force they know the best, which is a

weight.

Another instrument, the dynamometer has been introduced.

REStARTS –The Experiments

13

Depending on the age of the students, the gravity acceleration factor g can be measured and introduced.

Ask students to write a paragraph about their understanding of weight, mass and gravity and how they

could measure that (this can be a homework task or a task at the end of the lesson).

REStARTS –The Experiments

14

Objectives 1: To show that a static object (velocity equal to zero) is subject to balanced forces.

E x p l a n a t i o n

One of the common misconceptions: the static position is associated with the absence of forces, while in

fact, it corresponds to a balance of equal forces.

Experiments with balanced forces will be performed to demonstrate the presence of forces while a

balanced and static position is reached.

M a t e r i a l

Buckets full of water

Empty bottle of water (1.5 l)

Scales

String

M a x i m u m d u r a t i o n

45 minutes

M a i n q u e s t i o n s t o b e a s k e d

What do you think a force is? How do you know a force is present? How do you know forces work on a

stationary object? How do you know forces work on you when you are seated in your chair?

Introduction/Starters

Everybody stands up without moving. Ask the question: “did you feel a force on your body ? “

Then jump in the air “What‟s happening?”

When the students stands up again, ask them if a force is exerted on their body.

M a i n a c t i v i t i e s

Experiments: A fixed object is always subjected to balanced forces

Ask in each group, to one of the students, to stand up on the scale and to measure

the forces. Depending on their age, ask them to write on a piece of paper or to draw

the forces on the floor.

B. Weight of a bottle

REStARTS –The Experiments

15

1. Attach an empty plastic bottle to a string, let it fall. Again ask them how they understand what‟s

happening.

2. Fill the bottles with water, the ask them to gently (!) lower the bottle of water in the bucket full of

water, keeping the string in their hands.

3. Ask them to write down or draw step by step what happens

4. I carry the bottle full of water, I feel …

5. I lowered the bottle of water in the bucket, and the string …

6. They can repeat the same operation measuring the weight of the bucket before and after that the

bottle is within the water. Ask them to predict how the weight will vary.

C o n c l u s i o n / P l e n a r y

Forces are always present even if we don‟t always “feel” them. A stationary body is always submitted to

balance forces.

Ask students to predict which forces are working on a plane when it stands still on the runway before it

starts moving?

REStARTS –The Experiments

16

Objectives 1: Understand that the pressure is proportional to the surface on which a same force is

applied

E x p l a n a t i o n

The following activities will show by experiment the concept of

pressure, representing the force applied on a given area. If the

same force is applied on a larger area, the pressure decreases.

Another important aspect is that the pressure on a solid depends on

the contact area, while for a fluid (i.e. a liquid or a gas), the body is

immersed in the fluid so the pressure is applied on all the surface…

The following experiments correspond to the fakir bed experiments, difficult and dangerous to manage in

a classroom!

M a t e r i a l

Bucket full of sand and sand pit

Shoe

Snowshoeing

Stilt

Flat big container full of sand or sand pit

Wooden plate with 3 nails

Wooden plate with plenty nails

Scale

Plastic container full of modeling dough

Plastic containers of the same size

M a x i m u m d u r a t i o n

45 minutes

M a i n q u e s t i o n t o b e a s k e d

REStARTS –The Experiments

17

I n t r o d u c t i o n / S t a r t e r s

Go to a sand pit and ask the children to flatten the sand.

Then you tell them that you are going to put your feet in the sand with the stilt, the normal shoe and the

snowshoeing.

What do your students expect to see?

Ask what is the difference for them?

You can also show them the fakir and ask them why he seems so comfortable on his nail bed?

M a i n a c t i v i t i e s

Step 1 : 3 nails

Take a wood plate with 3 nails and put on the top a plastic container full of

play dough. What do they observe?

Put a light plastic glass on the top of the container. Add water until the nails

touch the bottom of the container.

Weigh the amount of water you add to reach the bottom

Step 2 : 20 nails

First add the same quantity of water as for step one

Then apply the same procedure with a wood plate with 20 nails. Add water

until it reaches the bottom of the plastic of water

Ask to the students to explain you need much more water before you

reach the bottom level

The way this experiment is proposed here is just to understand the principle of pressure with solid. You

can always apply a more scientific approach by varying parameters such us number of nails, thickness of

the play dough, changing the position of the glass of water, …

C o n c l u s i o n / P l e n a r y

When applying a given force on a solid surface, the resulting pressure will be function of the surface.

If the surface increases, the pressure decreases, and if the surface decreases the pressure increases.

Again quantification of this law will be made with students above 11 years old.

REStARTS –The Experiments

18

Objective 1 : Demonstrate that the pressure in the phase solid or fluid (liquid or gas) is different

E x p l a n a t i o n

Pressure is the result of a force applied on a given surface; because of their nature the surface of contact

of the fluid (liquid or gas) will be different from that of the solid.

The results will be that the force that has to be considered in a fluid will not be the same for fluid than for

liquid. Indeed if you put all the see in a reservoir and then you put your hand under the reservoir, the

pressure on your hand is due to all the weight of the sea water. While if you put your hand in the sea

water at a depth of 2m the pressure is that of the column of water above your hand. Let‟s experiments

this.

M a t e r i a l

Plastic bags in light plastic without holes!

Small and bigger plastic containers as light as possible (ice cream box)

Towels

Floor Cloth

M a x i m u m d u r a t i o n

30 Minutes

M a i n q u e s t i o n t o b e a s k e d

What is the difference between the pressure between a solid and a liquid or a gas?

M a i n a c t i v i t i e s

Put plastic containers in front of the group of students and ask them to put a plastic bag around

one hand

Ask them to dip their hands in the water container

Ask them to express their feeling about this experiment. How does the water act on their hand?

Then suggest that they plunge their hand (without plastic bags) into the bottom of the container.

Repeat this experiment taking first the small container with just a little bit of water and then with

as much water as possible. Do they feel a difference?

Repeat this experiment, with the same two levels of water you dip one hand at the bottom of the

container. Is there a difference between small and big containers?

Now take the small and the big containers with the highest level of water and put them carefully

on the top of your hand which is out of the water on the table!

REStARTS –The Experiments

19

Note that the container should be light so that its weight is negligible compared to the weight of the water.

This experiment is a step between experiments of the pressure of solid and fluid. At this stage ask your

students to express themselves and to react to these experiments. This can be done by drawing, writing

or speaking.

C o n c l u s i o n / P l e n a r y

During these experiments students should have felt pressure within a liquid and they have experimented

that there is a difference between a pressure within a fluid and with the contact of a solid.

REStARTS –The Experiments

20

Objectives 1: Observe that the pressure varies with the height of water.

E x p l a n a t i o n

The hydrostatic pressure of a given fluid is function of the height of the fluid above the considered point.

Holes are perforated in a bottle full of liquid, and the jet will be less energetic depending on the height

with respect to the water.

M a t e r i a l

The simpler version of this activity can be done using 1.5 or 2 -liter soda bottles taped together The more

sophisticated version consists of a pipe with one small exit hole drilled near the bottom and seven large

holes drilled along it and plugged with rubber stoppers. The separation between the hole centers is 5 cm

(can be varied)

Container with three different-size holes drilled at the same height (the holes should not be too small)

Large flat container

Ruler

Towels

Floor Cloth

M a x i m u m d u r a t i o n

45 minutes

M a i n q u e s t i o n t o b e a s k e d

I n t r o d u c t i o n / S t a r t e r s

M a i n a c t i v i t i e s

(Ref: http://www.tos.org/hands-on/teaching_phys.html)

REStARTS –The Experiments

21

1. You have a pipe with one small exit hole near the bottom and several large holes plugged with

rubber stoppers. You can fix the height of the water column above the exit hole by simultaneously

covering the bottom exit hole with your finger and filling the tube until water flows out one of the

upper large holes (after removing a stopper from the hole). Make sure you have placed the ruler

perpendicular to the bottom of the pipe.

2. Before you use this apparatus: What do you expect will happen when you fill the tube with water

to the height of the first large hole (from the bottom) and release your finger from the exit hole?

Explain your expectations in terms of the forces acting on the fluid. What do you expect will

happen when the water height above the exit hole is increased? Why?

3. Test your predictions. Begin by removing the rubber stopper from the lowest large hole.

Simultaneously, hold your finger over the small exit hole, and fill the pipe with water until it runs

out the hole the stopper was in. (Think: Why do we want to maintain a fixed water level within the

tube?) Using a ruler, measure the height of the water column above the exit hole. Then, remove

your finger from the exit hole letting the water run out, while you continually fill the pipe with water

to maintain the same height of water column above the exit hole. Note how far the water squirts

when it first strikes the ruler. Replace the stopper and repeat the steps for the next four holes,

working up one hole at a time.

4. Plot the distance at which the water hit the ruler as a function of the height of the water column for

each of the holes. Are the data consistent with your prediction in Step 2?

5. Would the distance that the water travels, for any given hole, change if the holes were bigger?

Why?

1. Take the second pipe (or box) (with three holes of different diameters), cover all three holes with

your finger(s), and fill the pipe with water. Place the ruler perpendicular to the bottom of the pipe.

Uncover one hole at a time and measure the distance at which the water first strikes the ruler.

Does your observation agree with your reasoning in Step 5 above (Part A)?

C o n c l u s i o n / P l e n a r y

REStARTS –The Experiments

22

Objectives 1: With this experiments students will observe that the pressure varies with the height of

liquid, making the experiments from inside the liquid.

E x p l a n a t i o n

M a t e r i a l

Transparent container

Glass of water

Small floating object

Soda plastic bottles with three different diameter

Or Plexiglas tubes with 3 different diameters

Take a piece of rigid material, that resist to water, light plastic for example

M a x i m u m d u r a t i o n

45 minutes

M a i n q u e s t i o n t o b e a s k e d

I n t r o d u c t i o n / S t a r t e r s

1. Do a simple experiment in front of the children:

2. Choose a transparent container full of water.

3. Put the small floating object on the water surface.

4. Then put a glass of water upside down and push it very horizontally, very straight, slowly into the

water.

5. Before starting to push, ask your students what they are expecting to see.

6. After the experiment, discuss with them why the glass is not full of water?

You can also propose them to do the experiments themselves.

M a i n a c t i v i t i e s

If you want to make a qualitative experiment, you can choose 3 rigid Plexiglas tubes with diameter of 2,5

and 10 cm

If your students are younger and the experiments is more qualitative, used aplastic bottles with volume

0,33l, 1,5 and 2,0 litres, from several sizes and cut the top and bottom to obtain cylinders of different

sizes.

REStARTS –The Experiments

23

A . T e s t t h e p a r a m e t e r h e i g h t o f l i q u i d

Close the bottom of the middle size tube with a piece of light rigid plastic.

Push the piece of plastic firmly and then dip the tube within your container of water at the half of

the height. If you did well the pressure should ensure the seal and the water does not enter the

Plexiglas tube

Question to ask your students: how much water will you need to add before the piece of plastic

will be released?

Do the same experiments, and stop filling with the water just before releasing the piece of plastic.

Then push your tube lower within the water. What do you have to do to release the plastic?

Conclude with the students, as the height of water increases, the pressure…

B . T e s t t h e p a r a m e t e r o f d i a m e t e r o f t h e t u b e

Perform exactly the same experiments as in 1) changing the diameter of the tube.

Refer to the experiments of session 1, if the pressure is the same both sides of the plastic, but the area

has increased the force applied on the plastic should increase more water.

C o n c l u s i o n / P l e n a r y

REStARTS –The Experiments

24

Objectives 1: With this experiment students will observe that the pressure varies depending of the

density of the liquid.

E x p l a n a t i o n :

M a t e r i a l :

Transparent container

Soda plastic bottles with three different diameters

Or Plexiglas tubes with 3 different diameters

Take a piece of rigid material, that resists water, light plastic for example

Fluid: Glycerol, Oil

Scale

Reference volume 100 ml

M a x i m u m d u r a t i o n :

45 minutes

M a i n q u e s t i o n t o b e a s k e d :

I n t r o d u c t i o n / S t a r t e r s

Ask the kids to put their hand in a hermetic plastic bag and again feel the pressure of water. Then take a

fluid with very high density and ask them to repeat the experiments.

What do they feel?

M a i n a c t i v i t i e s

Give them the 3 types of liquid: oil, water and glycerol and ask them to comment on these liquids.

Normally the aspect of weight will come out. Ask them how to compare these fluids in terms of

weight.

Propose them to weigh a given volume for each fluid.

At this stage we will repeat the experiments of session 4, replacing the water by the fluids which

are respectively more and less dense than the water.

REStARTS –The Experiments

25

Close the bottom of the middle size tube with a piece of light rigid plastic.

Push the piece of plastic firmly and then dip the tube within your container of water halfway up. If

you did well the pressure should ensure the seal and the water does not enter the Plexiglas tube

Question to ask your student: how much fluid less dense than water you will add before the piece

of plastic will be released?

Do the same experiments, and stop filling with the water just before the release of the piece of

plastic. Then push your tube lower within the water. What do you have to do to release the

plastic?

Conclude with the students, as the height of water increases the pressure…

C o n c l u s i o n / P l e n a r y

REStARTS –The Experiments

26

Objective 1: Demonstrate that air pressure varies in function of the height

E x p l a n a t i o n

This experiment is very interesting because it will show that, although we don‟t feel it, the pressure of the

air varies depending of the altitude. This experiment is optional because you need to have at least five

floors ( 15 m) of height to measure a difference. If it is not the case in your schools but some of your

students live in high-rise flats for example, you can always ask them to do it, make a film, and bring it

back to school.

M a t e r i a l :

Empty plastic bottle as rigid as possible, not necessary transparent.

If the bottle is not rigid the experiment does not work.

Play dough

Transparent plastic flexible tube 5 or 6 mm diameter

Water, if possible with a little bit of food colouring.

Play dough

M a x i m u m d u r a t i o n :

45 minutes

Main question to be asked:

When you will change altitude, going up or going down, ask your student how the air outside the bottle

will push with respect to the air within the bottle

I n t r o d u c t i o n / S t a r t e r s

What happens to your ears when you take the plane or when driving fast down in a tunnel or going up a

mountain?

M a i n a c t i v i t i e s

NB: This experiments works well but needs a little bit of practice before to do it.

Take a transparent plastic flexible tube 5 or 6 mm diameter, 40 cm long and fill 15 cm of the tube

with coloured water

REStARTS –The Experiments

27

Now the most difficult part of the experiment is to trap the air at the pressure of the altitude where

you are in your plastic bottle, to do this you need to close the aperture of the bottle around the

plastic tube with play dough. This needs at least two persons: one to fill with the play dough, the

other to keep the tube full of water.

Then you are ready to go up or down, the easiest is to perform this experiments in a lift

With younger children, observe the evolution of the pressure going down and up. Discuss with

them the difference of pressure within the bottle and the air from outside pushing less going up.

With older students you can quantify the variation of the water position going up and down

You can also “trick” your students and give to one of them a very soft plastic bottle with a thin wall

and do the same experiments. In this case the air will be a bit pressurised from outside and the

difference of pressure will be smaller than for a rigid bottle. Ask them to explain the difference

between the two cases (soft and rigid bottle).

C o n c l u s i o n / P l e n a r y

When going to higher altitude the mass of air above us decreases and consequently the pressure

decreases.

If this variation of pressure is fast we can feel it on our ears.

If we take the air in a closed bottle at high altitude take it to a lower altitude, the pressure of the air in the

closed bottle will be the pressure at high altitude, thus lower. Going down, the pressure around the bottle

is higher and the soft plastic bottle will be crushed.

REStARTS –The Experiments

28

Objective 1: Discuss the mental representation that your students have about gravity

E x p l a n a t i o n

Although we are subject to the earth‟s attraction force all the time, this concept seems vague for children.

Through several experiments, students will test several aspects of gravitation force: attraction force

between the earth and the objects …

An example of a misconception is that we are pushed by the atmospheric pressure towards? The earth.

M a t e r i a l

Ball

Feather

Sheet of paper

Heavy weight

Big object with a small weight

Tennis ball

Newspaper

Bathroom Scales (if possible non electronic)

M a x i m u m d u r a t i o n

30 minutes

M a i n q u e s t i o n t o b e a s k e d

What happens if you release an object?

I n t r o d u c t i o n / S t a r t e r s

Ask your students to mime gravity …

M a i n a c t i v i t i e s

Ask your students to perform several actions

Choose an objet and release it. What happens?

Take a sheet of paper and a small marble. Let them fall at the same time

Describe, what happen?

Throw something light in the air. What happens?

REStARTS –The Experiments

29

Jump in the air, What happens?

Ask your students:

How they explain what they have experienced ?

To stimulate the discussion, if you made the experiments on force before, you can give them one or even

two bathroom scales and ask them to weight themselves. What is this value they see on the scale ?

(NB: From 10 years old, children may be reluctant to weight themselves in front of other kids, in this case

you take a heavy object)

C o n c l u s i o n / P l e n a r y

Earth is attracting us and all objects.

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30

Objective 1: to show that when an object is falling, it is subject to two forces: gravity and friction

Objective 2: to experiment the effect of gravity, the influence of the friction force has to be minimised

Objective 3: to show that the acceleration due to the gravitation force does not depend on the weight of

the object

E x p l a n a t i o n

If you are releasing an object two forces are acting on the object:

1. the gravity force and

2. the friction force. The objective here is to make experiments that will reduce as much as possible

the friction force. When the friction force is negligible, the objective is to study the properties of

falling objects subject to the gravitation force. For younger students, the objective is to

experiment with them that the fall time for a given height is the same for a heavy object as for a

light object.

For older students, at secondary school, they will experiment that acceleration is constant. The

consequence is that velocity increases linearly with time.

The concept of friction will also be studed in the program of experiments on friction forces.

M a t e r i a l

Sheet of paper

Tennis balls

Syringe

Newspaper

Chronometer

M a x i m u m d u r a t i o n

45 minutes

M a i n q u e s t i o n t o b e a s k e d

Step one: why does the sheet of paper fall more slowly than the paper ball?

Step two: do heavy objects fall faster or slower than light objects?

REStARTS –The Experiments

31

I n t r o d u c t i o n / S t a r t e r s

You can show a small video to your students on falling objects on the moon, and in non gravity

atmosphere in order to discuss with them that the attraction forces can vary depending on the place you

are in the universe.

http://www.youtube.com/watch?v=isVO9AAAhxM&feature=related

More funny!

http://www.youtube.com/watch?v=SN77b9DqEbc

M a i n a c t i v i t i e s

Take a sheet of paper let it fall and measure the time before it reaches the floor.

Change the position of the sheet of paper when you release it, does it change anything?

Then make a ball of paper and let it fall. Compare the fall time.

What is the difference between these experiments?

Take two tennis balls, fill one of the tennis ball with water

Take sheets of paper and make a paper ball of the same diameter

Then let the balls fall two by two or three at exactly the same time. Put a sheet of newspaper on

the floor so you can hear the ball reaching the floor.

What are the differences between these three balls ?

What are the similarities in term of shape ?

What is the constant in terms of physics ?

Is the velocity constant ?

C o n c l u s i o n / P l e n a r y

Objects with a reduced friction force with different weights will take the same time to reach the floor.

During their fall their velocity varies.

During their fall their acceleration is constant and equal to the gravitational acceleration(g) (for secondary

schools).

REStARTS –The Experiments

32

Objective 1: How to generate a force that is opposite to gravity

Objective 2: Increasing friction force not in the air but in water

E x p l a n a t i o n

The objective here is to develop a more playful approach. In order to propose to the students to create a

force that is opposite to gravity, they will used this friction force that we tried to minimized in the previous

session

M a t e r i a l

Container full of water

Play dough with density higher than water (Sinking play dough)

Chronometer (optional)

Kitchen Scale

M a x i m u m d u r a t i o n

30 minutes

M a i n q u e s t i o n t o b e a s k e d

Challenge: Give to each group a play dough ball. They should make it sink as slow as possible

M a i n a c t i v i t i e s

Ask them to weigh a ball of play dough of 20g for each group.Ask them to make it sink; is it

possible to time the process?

Ask them to make the play dough float

Challenge them to make a contest between the different groups of student and make the play

dough sink as slowly as possible. Give them stop watchs to compare times.

REStARTS –The Experiments

33

C o n c l u s i o n / P l e n a r y

In this challenge, the winning group will be the one that manages to increase friction force by increasing

the surface of the play dough. They have to play on the opposite principle that they experimented in

session 2. By increasing the drag forces, increasing the area of the play dough they reduce the effect of

the gravity and the play dough is slowed down in its movement.

REStARTS –The Experiments

34

Objective 1: To understand that a two-dimensional object has a point of equilibrium.

E x p l a n a t i o n

The objective consists of investigating the position of the point of equilibrium of a two dimensional object

before moving to an airplane that is three-dimensional

M a t e r i a l

Cardboard (Cereal Packaging)

Scissors

Cord

Nails

Pencil

Bamboleo game

M a x i m u m d u r a t i o n

60 minutes

M a i n q u e s t i o n t o b e a s k e d

Can you find the point of equilibrium of an object?

I n t r o d u c t i o n / S t a r t e r s

Buy or build four games of the small version of Bamboleo and propose to four groups to play a game, or

buy the big version of Bamboleo and play a game with all of them.

Ask to your students to describe what happen in this game.

M a i n a c t i v i t i e s

Give your students a piece of light cardboard (for example cereal packaging) (10 x 10 cm)

Ask them to draw an two-dimensional object as large as possible

Ask them to take a pencil with the top part directed to the cardboard and then find the point of

equilibrium

Draw this point of equilibrium

Repeat the same operation for a circle, a square and a rectangle, observe where is this point for

these three regular shapes

Give to your students a nail and cord, and ask them to find a method to discover this point on the

initial irregular shape.

REStARTS –The Experiments

35

C o n c l u s i o n / P l e n a r y

REStARTS –The Experiments

36

Objective 1: To show that when air is moving, some unexpected effects are produced

Objective 2: To arrive at the conclusion that when air is moving faster it pushes less and vice-versa

E x p l a n a t i o n

The Bernoulli theorem considers conservation of energy law and is too complex to explain to young

students. The principle is that, in absence of compressibility effects, when a fluid is moving an increase of

pressure will generate a decrease of velocity and vice versa. If this may be too complex to explain to

them we can at least show them experiments where this “exchange” between velocity and pressure

generates surprising effects.

M a t e r i a l

A4 sheet of paper

Air balloons

A little bit of sand

A kebab stick

String

M a x i m u m d u r a t i o n

45 minutes

M a i n q u e s t i o n t o b e a s k e d

What is the difference if air is moving?

If the velocity increases does the air push more or less, than if the air is not moving?

Pressure and pushing: can you relate this two terms (for a 11 Year old ?)

REStARTS –The Experiments

37

I n t r o d u c t i o n / S t a r t e r s

These three objects are flying but not for the same reason, can you explain the differences?

M a i n a c t i v i t i e s

A. Phase of observation

- Paper experiment

Take with two hands 1/2 sheet of A4 paper

Put your mouth just on the upper part of the sheet and blow on it. What do you observe?

- Balloons experiment

Blow up two balloons,

Before closing them put a little bit of sand in it, so they are not moved by small draughts

Then attach to each balloon a string and attach them to a wood kebab stick. The balloon should

be separated by around 4 or 5 cm

Blow between the two balloons

What do you observe?

REStARTS –The Experiments

38

Possibly experiment with a funnel.

Can you find out what is common between those two experiments?

C o n c l u s i o n / P l e n a r y

The conclusion is that, in the two exp4eriments, when we are blowing, we give to the air a certain

velocity.

The air has a higher velocity on the upper part of the piece of paper and in between the two balloons.

Air does not move on the lower part of the sheet of paper and on the external part of the balloons.

The fact that the sheet goes up where the air is moving and the fact that the balloons stick to each other

where the air is moving, demonstrate that the air is pushing more … has more pressure when it is not

moving and the air is pushing less when it is moving.

This was discovered by Daniel Bernoulli in 1738, and is the basic principle of the lift of an airplane.

REStARTS –The Experiments

39

Objective 1: To build a small facility to test an airfoil

Objective 2: To link the lift on an airfoil to the experiments performed in session 1.

E x p l a n a t i o n

The explanation of acceleration of the air on the wing is very difficult

to demonstrate with simple experiments, and we would like to avoid

“to tell” a story to the students. This is why by comparison with the

previous experiments we would like that the students understand that

lift is generated because the air is accelerated on the upper part of

the wing and this acceleration is due to the shape of the wing.

M a t e r i a l

Small realistic model(s) of airplane where it is obvious that the wings have a higher curvature on

the upper part

Shoe box

Straws

Fine strong string

Paper

Hairdryer

M a x i m u m d u r a t i o n

45 minutes

M a i n q u e s t i o n t o b e a s k e d

Do you know the function of the wings on a plane ?

I n t r o d u c t i o n / S t a r t e r s

Give the children a model of a plane and ask them to look, touch, observe carefully the wing and ask

them what they observe.

You can also propose to the children to observe the image of this wing which corresponds to the root of

the wing where it is attached to the plane and observe that the lower part is flatter than the upper one.

REStARTS –The Experiments

40

M a i n a c t i v i t i e s

1. Prepare the wing

Take a piece of paper and turn it.

Then make a fold so the lower part is flatter.

Reinforce your wing structure by gluing 2 straws, that will help to guide it

2. Prepare the structure to maintain the wing

Take a shoe box and tender to strings.

Past your wing within the strings, check the stability.

3. Lift your wing

Blow on your wing with a hair dryer

This step can drawn on the result of a discussion.

According to the previous experiments, if the wing is lifted it is because the air is pushing …… ( more on

the lower part) which means that the velocity on this part is …… (slower)

And thus on the upper part ……. (air is faster and pressure lower)

This can be explained by the shape of the wings that forces the air to go faster on the upper part.

C o n c l u s i o n / P l e n a r y

The plane lift force is due mainly to a force directed opposite to gravity, occurring when the air is flowing

around the wing, and is decelerated on the lower part of the wing and accelerated on its upper part.

REStARTS –The Experiments

41

Objective 1: Showing that when air is moving, some unexpected effect are produced

Objective 2: Arrive to the conclusion that when air is moving faster it pushes less and vice versa

E x p l a n a t i o n

The Bernoulli theorem is a conservation of energy law to complex, to explain to young students. The

principle is that, in absence of compressibility effects, when a fluid is moving an increase of pressure will

generate a decrease of velocity and vice-versa. If this may be to complex to explain to them we can at

least showing them experiments where this “exchange” between velocity and pressure generates

surprising effects.

M a t e r i a l

A4 sheet of paper

Air balloon

A little bit if sand

A stick

M a x i m u m d u r a t i o n

45 minutes

M a i n q u e s t i o n t o b e a s k e d

What is the difference if air is moving?

If the velocity increased does the air push more or less, than if the air is not moving

Pressure and pushing: can you related this two terms ( starting 11 Years old ? )

I n t r o d u c t i o n / S t a r t e r s

M a i n a c t i v i t i e s

C o n c l u s i o n / P l e n a r y

REStARTS –The Experiments

42

Objective: Identify from our life experience the friction force.

E x p l a n a t i o n

Students all know intuitively the friction force concept. This session will make them feel through

experiments the friction force.

They will also experience modification of parameters that influence the friction like for example the fluid.

M a t e r i a l

Tanks full of water

Apple

Small and big racquets

Racquets with and without blocked holes

Cars (toys)

Piece of carpet

M a x i m u m d u r a t i o n

30 minutes

M a i n q u e s t i o n t o b e a s k e d

What is the friction force?

Is the friction force helpful in our life?

What is the difference between friction forces in solids and in fluids?

I n t r o d u c t i o n / S t a r t e r s

Put an apple in a tank full of water and ask a student to put his/her

hands in his/her back then to grab the apple, with his mouth. What

happens?

Then do the same experiments but put the apple on the table.

What is the difference?

M a i n a c t i v i t i e s

Move your hand in the air. Do you feel something?

Try the different small and big racquets, do the same

REStARTS –The Experiments

43

Move your hand in the water

Take a small racquet and move it in the tank of water

Discuss with your students about their interpretation of these experiments, and ask them to describe

other life experiences where they have already experienced this feeling.

Take small cars, ask them to roll on the floor

Ask them to repeat the experiment with different materials on the floor

Ask your students what is the difference between this experiment with the car, and the experiments with

the hand before.

C o n c l u s i o n / P l e n a r y

Friction forces will generate resistance to the displacement. In many

application research is devoted to reducing these frictional forces.

There is a difference between the friction in a fluid and the contact

friction between solids, but we have to keep in mind that we need

friction forces to move and to stay on the floor while we are walking

for example.

For example, in the case of a car when the car is moving it needs good tires, to have a good grip, but is

also needs a good aerodynamic profile to reduce the friction forces to consume less fuel.

In the case of the plane, the wings are profiled in order to have a good lift but also to minimise frictional

forces. When the plane is landing, the airbrakes placed on the end of the wings will be moved to increase

the friction forces to slow down the plane.

REStARTS –The Experiments

44

Objective 1: To experiments how to change a friction force.

Objective 2: To develop with the student an experiment in order to compare several test of friction

forces, and the effect of changing parameters.

E x p l a n a t i o n

From all the concepts we have discuss up to now, friction is the most approachable in terms of intuition,

at least in terms of slowing down a movement. This session will be dedicated to experimenting how to

slow down a movement generating a frictional force.

M a t e r i a l

Cars: Criteria to choose the cars: the car should not be too light, otherwise they are instable, but

they should not be too heavy, because they should roll quite far when you push them. After trying

different cars in common toy shops, we concluded that the best cars are the ones designed for

babies (18 mth). Since they are not very strong and not very accurate in general those cars roll

well.

Car ramp, simple slope: Either you build it yourself or you take a kid‟s car ramp. The main point of

a good ramp is that the passage between the floor and the ramp should be as smooth as

possible. This is why most of the time the ones you can buy are thin and curved.

Sheets of paper

Straws

Adhesive paper+

M a x i m u m d u r a t i o n

45 minutes

M a i n q u e s t i o n t o b e a s k e d

How to reduce the displacement of this car?

How to build an experiment to compare our tests?

I n t r o d u c t i o n / S t a r t e r s

Look with your students at these two pictures and ask them why cyclists and speed skiers have those

special equipments. Also ask them to look at the position they take and discuss it.

REStARTS –The Experiments

45

M a i n a c t i v i t i e s

Give to your students in groups of 3, one ramp and one car. Ask them first to check the distance the car

reach if they release it on the slope.

The challenge consists to transform the car to reduce as much as possible the displacement of the car

without touching the wheel system, and without changing too much its weight

Students have performed experiments, where they could only compare their own tests because they have

all vary the parameters in several ways. Propose them for the next session to organise a contest but

fixing parameters.

Discuss with them what are the parameters that have to be fixed, and which ones they will vary to study

the impact of the friction force.

If they want to compare their tests they should release their cars the same way: from the same

height on the ramp, and very parallel to the border

They can vary the shape of the surface and the value of the surface

They can also make volume and discuss how to determine the surface

C o n c l u s i o n / P l e n a r y

By adding area that resists to the air, the car is slowed down in its movement, and its displacement is

reduced.

REStARTS –The Experiments

46

Objective : Experiments with a scientific approach to the modification of area resisting motion.

E x p l a n a t i o n

M a t e r i a l

Cars

Criteria to choose the cars: the car should not be to light, otherwise they are instable, but they

should not be to heavy, because they should roll quite far when you push them.

After, trying different cars in common toy shops, we arrive to the conclusion that the best cars are

the one‟s designed for babies (18 mth), since they are not very strong and not very accurate in

general those car are rolling well

Car ramp, simple slope

Either you build it yourself, either you take kids car ramp, the main point of a good ramp, is the

fact that the passage between the floor and the ramp should be as smooth as possible, this is

why most of the time the one you can by are thin and curced

Sheets of paper

Straws

Adhesive paper

M a x i m u m d u r a t i o n

45 minutes

M a i n q u e s t i o n t o b e a s k e d

I n t r o d u c t i o n / S t a r t e r s

Discuss with your students what happened in the previous session and how you are going to organise

this one.

M a i n a c t i v i t i e s

Test with your students if the launching system of the car is reproducible, because they 6have to

launch several times their car and measure the travelled distance.

Then propose they can start their first parameter for example with a simple square. They can

measure the travelled distance, and then double the square area and measure again.

REStARTS –The Experiments

47

Then they can also take difference shapes, e.g. square, rectangle and circle, and perform the test

with exactly the same surface but for different shape.

They can try a volume built in paper, to avoid increasing too much the weight of the car, and

building a cylinder or using a ping-pong ball.

Mathematical aspects: again depending of the mathematical progress of your students, you can perform

several mathematical exercises, to compare areas. You can either do it geometrically by folding a piece

of paper if they are young (this works for triangles, squares and rectangles) of if they are older they can

apply the formulae they have learnt.

C o n c l u s i o n / P l e n a r y

REStARTS –The Experiments

48

Objectives 1:

E x p l a n a t i o n

M a t e r i a l

….

M a x i m u m d u r a t i o n

45 minutes

M a i n q u e s t i o n t o b e a s k e d

I n t r o d u c t i o n / S t a r t e r s

M a i n a c t i v i t i e s

C o n c l u s i o n / P l e n a r y

REStARTS –The Experiments

49

Objectives 1: Understand the thrust through the explanation of an aircraft motor

M a t e r i a l

M a x i m u m d u r a t i o n

60 minutes

M a i n q u e s t i o n t o b e a s k e d

I n t r o d u c t i o n / S t a r t e r s

M a i n a c t i v i t i e s

C o n c l u s i o n / P l e n a r y

REStARTS –The Experiments

50

Objective 1: To understand that a two-dimensional object has a point of equilibrium.

E x p l a n a t i o n

The objective consists of investigating the position of the point of equilibrium of a two dimensional object

before moving to an airplane that is three-dimensional.

M a t e r i a l

Cardboard (Cereal Packaging)

Scissors

Cord

Nails

Pencil

Bamboleo game

M a x i m u m d u r a t i o n :

60 minutes

M a i n q u e s t i o n t o b e a s k e d :

Can you find the point of equilibrium of an object ?

I n t r o d u c t i o n / S t a r t e r s

Buy or build four games of the small version of Bamboleo and propose to four groups to play a game, or

buy the big version of Bamboleo and play a game with all of them.

Ask to your students to describe what happen in this game.

M a i n a c t i v i t i e s

Give your students a piece of light cardboard (for example cereal packaging) (10 x 10 cm)

Ask them to draw an two-dimensional object as large as possible.

Ask them to take a pencil with the top part directed to the cardboard and then find the point of

equilibrium..

D r a w t h i s p o i n t o f e q u i l i b r i u m

Repeat the same operation for a circle, a square and a rectangle. Observe where is this point for these

three regular shapes.

Give to your students a nail and cord, and ask them to find a method to discover this point on the initial

irregular shape.

REStARTS –The Experiments

51

C o n c l u s i o n / P l e n a r y

REStARTS –The Experiments

52

Objective 1: To determine in which direction a plane is able to move.

Objective 2: To investigate that changes of direction happen around one point,

which is the gravity center.

E x p l a n a t i o n

M a t e r i a l

Small model of airplane

M a x i m u m d u r a t i o n

45‟

M a i n q u e s t i o n t o b e a s k e d

What is the main difference between the displacement of a plane and the displacement of a car?

I n t r o d u c t i o n / S t a r t e r s

Propose to the children to take a model of an airplane and ask them to show you in which direction a

plane can move when it is moving.

When all of them have finished their experiment, ask them where they have put their hands to handle the

place. Make them realise that none (normally) have taken the plane by its tail for example.

Take a model of a car and ask them to do the same, putting the car in a normal position on the floor, and

not in the air, what is the difference?

Normally, all of them will handle intuitively it around the gravity centre. That is what we are investigating.

M a i n a c t i v i t i e s

Give them the …. and ask them to build an object that looks like a plane with two wings and a tail and put

it in equilibrium on a tooth pick.

Then demonstrate how you will have to push to change the directions of the plane on the different axis.

Give them the sheets added in appendix to learn the exact aeronautical terms.

C o n c l u s i o n / P l e n a r y

REStARTS –The Experiments

53

Objectives 1: Build and Fly a paper plane

Objective 2: Changing the Flying direction of a paper plane

E x p l a n a t i o n

It is relatively easy to build paper planes and to modify their shape to change the direction they take.

Students will build these planes and then compare the direction they take with the real equipment of

planes

M a t e r i a l

A4 sheet of paper

M a x i m u m d u r a t i o n

45‟

M a i n q u e s t i o n t o b e a s k e d

How do planes change directions?

I n t r o d u c t i o n / S t a r t e r s

Ask the students to summarise the previous session about the directions taken by the planes.

Ask the students how they think that planes change direction?

M a i n a c t i v i t i e s

REStARTS –The Experiments

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P a p e r p l a n e c o n s t r u c t i o n

Prepare a paper plane according to the drawing above starting from an A4 sheet of paper.

Fly your paper plane and observe it.

Fold your paper plane according to the drawing below.

Which direction do you think your plane will take?

Fly your paper plane and observe it.

Fold your paper plane according to the drawing below.

Which direction do you think your plane will take?

Fly your paper plane and observe it.

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Fold your paper plane according to the drawing below.

Which direction do you think your plane will take?

Fly your paper plane and observe it.

Take the picture of a real plane and compare the different parts to the action we just saw.

C o n c l u s i o n / P l e n a r y

With a simple experiment using a paper plane it is possible to understand the functionality of the different

moving parts on a plane.

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Objectives: The impact of noise on the environment is one of the goals in greening air transport of the

European Union as mentioned in the Flightpath 2050 vision.

Therefore, understanding the process of noise generation and noise reduction plays a major role in the

achievement of the goals set and will be an important issue in future research in aeronautics. Qualified

and motivated personnel are needed in the long run in order to ensure the infrastructure on this field of

research in the future. Introducing the basics about sound and noise in schools is a good way to promote

young people‟s interest in aeronautics and its related fields.

Flightpath 2050 - Europe’s Vision for Aviation:

“The perceived noise emission of flying aircraft is reduced by 65%. These are relative to the capabilities

of typical new aircraft in 2000.”( Flightpath 2050 - Europe‟s Vision for Aviation Report of the High Level

Group on Aviation Research Page 15; (status as of 2012/02/13) )

As we know from our daily experience sound and noise play an important role in aeronautics. This is the

first of six lessons about sound and noise in which the pupils will learn

how sound is generated

the principle of a sound source

Acoustic sources are connected with mechanical vibrations. Their properties can be described by means

of their amplitude (maximum deflection) and their frequency (number of oscillations per time unit).

M a x i m u m d u r a t i o n

40 minutes

M a t e r i a l

CD player or computer with loud speakers to play sound samples as introduction,

box with rubber band (fig 1) or slats with nails to span a rubber band

ruler (fig 2)

tuning fork

glass & water

paper, drum (tambourine)

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triangle

bottles & water

Hint: It is not necessary to provide all of the material mentioned above, but you should offer at least 3-4

different materials, each generating sound in a different way. (e.g. tuning fork & glass filled with water,

ruler, box with rubber band.)

fig.1 Box with swinging rubber band

Put the rubber band over the long side of the box so that it spans across the middle. Pluck easily on the

rubber band.

fig. 2 The swinging ruler

Press with your hand one end of the ruler to the edge of a table; half of the ruler should reach over the

table (fig 2). Pluck at the free end – soft then strong – so it swings.

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I n t r o d u c t i o n / S t a r t e r s

Ask the pupils what in their environment makes sound or what typical sounds they can hear in

their daily life.

Ask them, if the examples are “nice” sounds or annoying sounds. Make a list.

Play sound samples (music, traffic noise, conversation sound, Thunder). Let them guess, what

the sound sources are.

State that because all of the mentioned things on the list generate sound they must have

something in common. Let the pupils discuss it.

M a i n a c t i v i t i e s

How can you generate sound?

What happens if sound is generated? Describe what you observe by seeing, hearing, feeling.

Explanation: The pupils should perceive that all used materials vibrate as a common property of sound

sources. You can use a loudspeaker to show that we can listen to music because of the vibration of the

loudspeaker membrane. They can touch the membrane carefully while playing music to feel the vibration.

How can the generated sound be influenced?

What makes the sound louder?

Can the sound/tone be influenced (not working on a tuning fork or a triangle)?

How to stop the sound?

What does happen?

What can be observed?

What have the different methods of sound generation in common?

Write your experiences in two “the more/less… the…”- sentences and describe the produced

sounds with the words “loud/silent” and “high/low (bright/dark)”

Explanation: The pupils should recognize that the deflection (amplitude, path) of the oscillating body

influences the volume of the sound. The higher the deflection the louder the generated sound. The faster

the oscillation (higher number of deflections per time unit, higher frequency) the higher is the tone pitch. If

they stop the vibration the sound is stopped, too. If the deflection decreases over the time, the sound

becomes quieter.

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Explanation: Pupils can feel the vibration of their vocal chords by touching their throat while speaking or

holding a balloon with both hands in front of their mouth while speaking. The vibrations can be felt.

Explanation: No vibration can be felt on the throat, as the throat and vocal cords are not involved. The

sound is produced solely by the lips (vibration). Another example is blowing over the orifice of a bottle

(with different water filling levels) also air can vibrate and thus produce sound.

C o n c l u s i o n / P l e n a r y

There are many ways to generate sound, for example by pulling a string or hitting a drum. The source of

a sound in these cases is always something moving back and forth rapidly, a vibration. If the vibration

stops the sound stops too.

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Objectives: Humans can distinguish between the sound of a plane and the sound if a helicopter. Some

people can even distinguish different types of planes only by hearing them. In this session the pupils will

learn

what a time signal is and how it looks like

how the frequency analysis is used as a tool for sound and noise analysis.

Oscillations are periodic movements characterized by their amplitude and their frequency. By visualizing

the time signal of a sound the pupils can “see” the movement.

With a frequency analysis of different sound sources (especially single tones) they can move on to a

concept of sounds as a combination of different frequencies. This may help them to understand the

nature of an “acoustic colour” and the difference between sound and noise.

The pupils should have knowledge about frequency or this session can be used to explain it.

Cooperation with a music teacher is useful to explain overtones.

M a x i m u m d u r a t i o n

90 minutes

M a t e r i a l

Signal generator & Oscilloscope or software for PC (e.g. “Scope” “Audacity”)

Soundcard and microphone

Different sound sources (see session 1)

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I n t r o d u c t i o n / S t a r t e r s

Play music on a computer with windows media player. Turn “visualisation” to “graph”. The time-signal of

the music will be displayed while playing. Questions: What is shown in the visualisation? How could we

use that?

Play music on a computer with windows media player. Turn “visualisation” to “bars”. The spectrum of the

music will be displayed while playing. Questions: What is shown in the visualisation? How could we use

that?

M a i n a c t i v i t i e s

Use a microphone with an oscilloscope to visualize the time signal. If no oscilloscope is available use a

computer with soundcard and oscilloscope software (e.g. “scope”).

Explanation: Explain that the signal detected by the microphone shown in the oscilloscope is proportional

to the air vibrations (or pressure / density variations) caused by the sound signal.

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Switch to frequency analysis. Make different sounds (whistle, hum, clap…) in front of the microphone and

watch the meter. Try to whistle a tone with increasing pitch like when you call a dog. What is shown on

which axis of the diagram? What does it mean when the graph is high on the left or right side of the

diagram? When do we get peaks?

Explanation: In frequency analysis tools we have the sound level drawn on the vertical axis, the frequency

on the horizontal axis running from low frequencies (“low tones”) on the left to the higher ones on the

right. As an analogy you can use a piano, where the lower tones are played on the left and the higher

ones are played on the right side of the keyboard. So we can see higher amplitudes on the left side when

sound with more energy in the low frequency range is analysed. In every case we hear tones we will see

peaks in the spectrum. The level is measured in Decibel (dB) with the highest possible level being the

maximum level of the soundcard. Normally this level is set as “zero” so that any other levels in the range

of the sound card are negative. For a soundcard recording with 16 bit dynamic range the sound level

without any noise is

-96.3 dB.

a) Observe the spectrum which you record when there is “no” noise in the room. What do you measure?

What do you hear?

Explanation: The microphone is still recording/detecting sound, even when it is “quiet” in the room. The

background noise of breathing, air fans, noise outside the room, rustling of clothes etc. won‟t get the line

to the ground. Even when these noises would miss, the electronics of the microphone and the soundcard

would still produce some noise. When you do measurements you will have to keep that in mind to

distinguish the sound you want to measure from the background noise.

b) Measure the spectrum of a plucked string and/or of a sung (or “robot-like” spoken) vowel. List the

frequencies of at least three of the lowest peaks and find a mathematical rule, which would create such

frequencies.

Hint: Divide the higher frequencies by the lowest frequency.

Explanation: Most tonal sounds are produced by vibrating strings or air columns. Due to standing waves

these vibrate with every possible frequency at the same time, thus producing a fundamental tone and

overtones/harmonics with frequencies being multiples of the fundamental one. Our hearing will combine

all these peaks in the spectrum to one single perception of a tone with a certain “colour”. The differences

of the overtone-levels varying from vowel to vowel will help us distinguish a “u” from an “e” and

understand speech.

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c) Measure the spectrum of a tuning fork and draw a sketch of the measured curve

Mind the right labelling of the axis. What would the spectrum of two tuning forks with different tones

sounding simultaneously be like? Measure the main frequency of the forks sound.

Hint: You can amplify the tuning forks by using a resonant body like an open box or the table. You can

tune forks by adding mass, e.g. wrapping a paper clip around the vibrating parts.

Explanation: This should give a peak in the measured spectrum concerning to the main frequency of the

tuning fork. Two different forks should show two peaks in the spectrum. In software like “scope” you can

use a drag-and-drop-cursor to easy measure frequencies. Tuning forks have poor overtones/harmonics

so a single peak for one fork should be seen in the spectrum. May be some harmonics can be detected

but with an obvious smaller amplitude.

(e.g. “white noise” of a noise generator or a radio/tv without being tuned to a station, a spoken “shhhh”)

and draw a sketch of the measured curve. What are the differences to the spectrum of the tones?

Hint: You will need a higher volume for the noise than the tones for a proper measurement.

Explanation: The spectrum of ideal white noise is a flat line, showing that there is the same energy in

every frequency (same sound levels). The measured spectra should be more “curvy” according to the

quality of the speakers, the microphone or the mouth position. In random noise the sound energy is more

or less evenly distributed to many frequencies as opposed to tonal sounds where the energy is

concentrated in one or more peaks.

and rate them according to their disturbance (e.g. fan noise, traffic noise, aeroplane noise, wind noise,

white noise). Is there a correlation between the rating and the “peakyness” (=tonality) of the spectrum?

Explanation: An important psycho-acoustical parameter is the tonality of sounds. In most cases noises

with tonal components will be rated to be more disturbing than noises with more “flat” spectra.

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C o n c l u s i o n / P l e n a r y

A sound spectrum shows how the sound energy is distributed to different frequencies. Tonal sounds

show a spectrum with one or more peaks. Random noise shows a continuous spectrum with a flat line.

Realistic sounds combine both elements.

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Objectives: To protect the public against excessive noise exposure regulations about noise emissions

were enacted by the European Union

(e.g. Environmental Noise Directive - Directive 2002/49/EC, END). The implementation of the directives in

the member states includes physical measurable quantities such as the sound pressure level to describe

the emissions.

In this session the pupils will understand

how to quantify the volume of sounds

the reason for the usage of a logarithmic scale

what noise is.

The main question of this session is how sounds and noise can be measured. Therefore we need

knowledge about the sound pressure level and the usage of the dB scale.

M a x i m u m d u r a t i o n

90 minutes or even more if you do the excursion mentioned in 3.

M a t e r i a l

Sound files with listening samples (not only music but also sounds from the neighborhood,

machines)

Loudspeaker

Sound level meter

PC

Microphone, signal generator (on computer or external)

Empty sound level charts

Sets of different weights (1g, 2g, 5g, 10g, 20g, 50g, 100g)

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fig 6 Sound pressure level over pressure to demonstrate the logarithmic scaling of the dB scale

I n t r o d u c t i o n / S t a r t e r s

What makes noise in your environment? Make a list of annoying sounds.

Let the pupils do an assessment of different sound samples (Chat, whisper, music, ventilator, traffic

noise). What is loud / quiet / annoying / pleasant? Make a list with the collected information.

Be quiet, what do you hear?

Hint: Adjust the volume of the sounds to their actual sound pressure level (SPL) prior to the presentation

if possible. Beware of the fact that the sound pressure level decays with distance to the sound source, in

this case the loudspeakers. To adjust the volume you will need information about the SPL of a sound and

the distance between measurement point and sound source. Measure A-weighted SPL in dB(A).

M a i n a c t i v i t i e s

1) What would you measure to describe the volume of a sound or noise? How can we describe

(characterize) the pressure fluctuations in an appropriate way?

And how would you do it?

Explanation: A sound wave is a fluctuation of pressure (physical unit is Pascal Pa), so physically we

measure pressure values to describe the volume of sounds. To measure the sound pressure level (SPL)

a microphone can be used. As in session 3 the sound energy is transmitted from the source to the

membrane of the microphone in the form of a wave. This pressure fluctuation causes the vibration of the

membrane which can be measured electrically. The principles are the same as in a loudspeaker, where

an electrical signal causes the vibration of the membrane, but the other way around.

2) Use one set of weights per group of pupils. One should take one weight on the palm of the hand (not

too light, for example 50g or 100g) and close his/her eyes. A second pupil should try to place a second

lighter weight on top of the first one, may be placing a piece of paper between the weights to avoid any

noise. Can you feel with closed eyes the additional weight? When does it become heavier? Note the

values “original weight” and “additional weight” in case of feeling the additional weight.

Explanation: When placing 10% of the original weight on top of it, one should feel the additional weight.

Below this threshold you may hear it or feel the pressure during placement. But it is very difficult to feel an

additional weight of 1g when holding 50g in your hand. When you calculate (original mass + additional

mass)/original mass you should get something around 1.1. This means you need 10 % of the original

weight to register a change in weight. This is not a linear behaviour and the same principle can be found

in hearing. In fact, it is a logarithmic (with base 10) behaviour which means you register an increase in

volume when the pressure is increased by 10 to 12%.

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67

The sound pressure that a human ear can detect varies from 2*10-5

Pa (20µPa) at the Threshold of

human hearing to 100 Pa at the Threshold of pain. It is remarkable that our ears can distinguish such a

huge range of pressure. For making out the difference between the sound of a mosquito and normal

speech on one side and recognizing loud sounds like a starting airplane on the other side the sound

pressure is not perceived in a linear way by the human ear.

To take this effect into account the sound pressure level (SPL) was introduced and with it a scale from 0

dB to 130 dB is available. In this scale 1 dB is an audible volume increase. The SPL is a measure of the

effective sound pressure p relative to a reference value p0. This is needed because of the use of the

logarithm in the definition of the SPL

SPL = 10*log(p2/p0

2) = 20*log(p/p0)

with p0 as reference value (2*10-5

Pa) which was defined according to the threshold of audibility at 1 kHz.

This value has no physical unit but is marked as sound pressure level by adding dB (decibel). Show a plot

of SPL versus pressure to illustrate the logarithmic scale (fig. 6).

3) Organize an excursion in your area to measure sound levels of daily sound sources. Let the pupils take

notes, put them together and use this in 5.

Hint: It is good to note the distance between sound level meter and source, the SPL, the kind of sound or

noise (car and barking of a dog for example), the feeling of the pupils about the source and its sound and

the duration of the sound (like “the whole time”, “3 barks”, “one car in city speed driving by in 10

seconds”)

4) Play the sound samples of different sound sources from the introduction again. Let the pupils measure

it with sound level meters. They should take notes on cards about the SPL, the distance to the

loudspeaker and the kind of sound. Use them in 5 to discuss different aspects of sound and noise.

5) Show examples of different sources and their sound pressure level. If you made an excursion with the

pupils, use their notes, too. Discuss the dB-scale. What kind of description is connected to the SPL?

What cannot be explained with the SPL?

Hint: Prepare some cards (size of a postcard) and write the name of the source and its sound pressure

level on the card. The pupils can do the same with the measured sources during the excursion. Put them

together in a chart, low sound pressure levels at the bottom and high sound pressure levels on top. The

pupils can also make a poster for the classroom from the postcards.

Explanation: Discuss the scale and the placing of the sources in the chart. The pupils should get an

impression and a feeling for the dB scale. If possible, discuss the influence of distance to a source on the

SPL.

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Ask them:

a) Can you identify loud or quiet sounds with the sound level meter? What sound pressure level do you

measure in a quiet room without talking and moving around?

Explanation: Loud and quiet sound can be distinguished by comparing the numbers on the display. A

smaller number is less loud than a larger number. Even in a very quiet room you can measure a sound

pressure level higher than zero dB (noise coming from outdoor, pupils moving around and so on). It is

possible to measure less than zero dB as the reference for calculating the sound pressure level is 2*105

Pa. Therefore you have less than zero dB if you measure a sound pressure below this reference.

b) Can you identify annoying or pleasant sounds with the sound level meter? Why not? Discuss this

point!

Explanation: This is not possible by measuring the sound pressure level because annoyance and

pleasure are connected to judging. Because everybody uses his or her knowledge and experiences to

identify annoying sounds the judging is a very individual process and not only connected to the pressure

level. It is not an exactly measurable physical quantity.

c) What is noise? Is it connected to annoyance? Which kind of sound is annoying and when does it

become noise?

Discuss which sound pressure levels are disturbing, which causes damage (are unhealthy) and which

destroys our ears immediately. Use the chart from 5 to discuss what the differences between sound and

noise are.

Explanation: With a sound level meter showing the SPL it is not possible to get information about the

frequencies of the sound and this is a second reason why annoyance cannot be measured with a simple

sound pressure level. An annoying and/or unwanted sound is defined as noise (see if you can find more

than this definition).

d) Do this experiment outdoor far away from walls to show the effect. Let the pupils measure the SPL in

distances of 1m, 2m and 4m to the speakers while playing a continuous sound sample (random noise for

example). Let them discover that a doubling of the distance to the sound source causes a 6 dB(A)

decrease in SPL.

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Explanation: The small loudspeaker can assumed to be a small source radiating sound in every direction

the same way. This leads to a spherical sound wave. As analogy you can bring the picture of throwing a

stone into a lake to the pupils mind. The stone causes a circular wave on the water surface travelling

away from the central point. While travelling away from the central point, the radius of the wave expands.

The same happens with a spherical wave in air. If you double the distance to the source, let us say from

1m to 2 m, the surface of the sphere increases from S1 = 4πr2 = 12.57 m

2 to S2 = 50.27 m

2. With this the

SPL will be attenuated by ∆L = 10 log (S2/S1) = 6 dB(A) because the radiated energy is uniformly

distributed on the small and the bigger sphere. Keep in mind that reflections influence the spherical wave

radiation.

C o n c l u s i o n / P l e n a r y

In this session the pupils should experience the quantity of sound levels in daily life. They should have

built a connection from the physically measureable pressure to the dB scale and realise that the distance

to the source plays an important role.

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Objectives: When trying to catch sight of an airplane in the sky we first follow our hearing impression and

realize that in many cases the plane can be found at a different place.

Humans are able to detect the direction from which a sound is coming from. But as the speed of sound

differ observable from the speed of light it gets more difficult with increasing distance to the source. In this

session the pupils will

experience the accuracy of the humans ability to detect the direction of a sound source

understand the technique the human brain uses for this (recognizing the delay between the

sound reaching left and right ear depending on the distance to the source)

perceive the finite speed of sound, which is responsible for the time delay between the ears.

Sound waves propagate with a speed depending on the media they travel through. In Air at 20° C sound

propagates with a speed of 343 m/s. This can be experienced for example in a thunderstorm. The light of

a flash reaches the eyes nearly immediately while the sound of the thunder needs some time to reach our

ears. The human ears can detect a time delay of a sound signal down to 30 µs and thereby are able to

detect a direction very precisely.

M a x i m u m d u r a t i o n

30 minutes

M a t e r i a l

Tube

2 funnels

Starting clap board or a pair of wooden blocks

Stop watch

Tape measure

fig 7 Starting clap board for measuring the speed of sound

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fig 8 Tube with funnels for the experiment “directed hearing”

fig 9 Two pupils doing the experiment “direction hearing”

I n t r o d u c t i o n / S t a r t e r s

Talk with the pupils about sound source detection. Do they think they can determine the direction from

where a sound is coming from? How accurate do they think they can do it? How can they do it? What is

the speed of sound and how can we measure it?

M a i n a c t i v i t i e s

Directed hearing: the two funnels get plugged to the tube, each on one end. One pupil holds both ends to

his ears with the tube behind his back. Another one knocks with a pencil on to the tube somewhere

around the middle. Now the listening one tells on which side it was knocked on. Discuss how this may be

possible.

Measure the speed of sound using a starting clap board or pair of wooden blocks:

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Find a building with a large, flat outside wall and enough free space in front, so that you can hear an echo

coming back from it. Stand as far away from it as possible and measure the distance to the wall. One of

the pupils is equipped with the starting clap board and another one with the stop watch. The time starts

with the first clap, the pupil with the starting clap board claps again as soon as he can hear the echo. He

does this ten times. Then the other one stops the time. Now they can calculate the speed of sound by

dividing twice the distance to the wall by 1/10th of the time for the ten claps. (Maybe for younger pupils:

use a ball to demonstrate “reflection” prior to the experiment)

C o n c l u s i o n / P l e n a r y

Sound waves propagate with a speed depending on the media they travel through. This causes a time lag

in the sound signals received at different distances to the sound source. In this session it should be

understood, that because of the finite speed of sound a detection of the direction of a sound source is

possible. Bats, whales and dolphins use this effect to navigate. They send out a signal and wait for the

echo to locate obstacles.

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Objectives: The used insulation material behind the body shell of a plane is used not only for thermal

insulation but also for noise insulation (see fig 10).

This is one example for noise reduction in airplanes. Beside this science and industry work on new

concepts for aircrafts to reduce their noise emissions. In this lesson the pupils will understand

that there are different concepts of noise reduction

the three main strategies of noise reduction:

sound reduction at the sound source,

sound reduction by restraining the transmission of sound;

noise cancellation (active noise control) using anti-phased signals.

To reduce the negative effects of noise on humans there are mainly three different approaches. The first

is to reduce the sound directly at the sound source, for example by technically avoiding it. The second is

to restrain the transmission of the sound by using insulating and absorbing materials or increasing the

distance to the sound source. The third one is to use interference of sound waves to actively reduce the

noise; this is called “active noise control”. These basic principles of interfering into the sound generation

and transmission lead to a manifold of technical applications to reduce noise. An example is the

disturbance of the transmission. It can be done directly at the sound source by encapsulation or by using

insulating earplugs directly at the listeners ear or somewhere in between for example with an insulating

wall. Another example the noise cancelation can be done by generating anti-phased signals close to the

listener. This technique for example is used in so called noise cancellation headphones which include a

microphone and a processor to invert the original signal.

M a x i m u m d u r a t i o n

45 minutes

M a t e r i a l

Alarm clock

Tuning fork

Aluminium plate

Dlay dough

Sticky tape

Pc and loudspeakers

Software with a frequency generator like “scope”

Something insulating like a blanket or a cushion

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fig 10 Insulation in an airplane

fig 11 Two loudspeakers to show active noise cancellation effect

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fig 12 Principle of noise cancellation, in this idealized case the phase shift of 180° causes perfect noise

cancellation

fig 13 Problem in noise cancellation applications: a phase shift other than 180° causes an amplification

I n t r o d u c t i o n / S t a r t e r s

Play some sound samples of traffic noise like starting airplanes or passing trains/cars. Talk with the pupils

about the effect of these noises on passengers and residents. Ask them what ideas for possible solutions

they have in mind. Insulating walls near a railway track? What about airports?

M a i n a c t i v i t i e s

1) Let the children play around with different sound producing items from session 1 and try to reduce the

sound level.

Remember the effect when you hold a tuning fork with its end to a table, it amplifies the sound. Now let

them try to disturb the sound generation by sticking some play dough to one or both of the upper arms of

the tuning fork.

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76

If an aluminum plate is available make some sounds by hitting it. Then coat most parts of the plate with a

thin layer of sticky tape and hit it again on a non-coated area.

2) Remind the pupils of the experiment with the alarm clock in vacuum. Explain that the reason for the

decreasing sound volume is an interruption of the sound transmission. Let them think about other ways to

do this. Maybe use a blanket over the alarm clock and measure the sound level. Try it with different things

like a box or a cushion.

Also talk about the experiment with doubling the distance to the sound source. It caused a reduction of

the sound level of 6dB.

3) Use the software “scope“ on a computer to generate two inversely phased sine signals (left and right

channel) one for each of the two speakers. Connect only one speaker at a time and let the pupils

measure the sound level with a sound level meter. Position the two speakers side by side (see fig 11),

connect both and let them measure again. You will notice a hearable decrease of the sound volume. The

sound level meter will show a decrease of around 10 dB. This is the principle of anti-noise, the two sine

waves cancel each other out. You do not need the box to show this effect.

Hint: Use a sine signal with a frequency of 200 Hz or 400 Hz to show the effect.

Explanation: As shown in fig 12 two sine waves shifted by 180° cancel each other out. The picture

shows the idealized case with two plane waves. In the experiment the two loudspeakers produce more or

less spherical waves. If the distance between the loudspeakers is small enough, you can hear the

attenuation but not a complete cancellation. In fig 13 the problem with this noise reduction method is

illustrated. A phase shift other than 180° results in an amplification. In this case it is better to turn off the

second source.

C o n c l u s i o n / P l e n a r y

The optimal way of reducing noise is to reduce it directly on the sound source itself. If this is impossible

insulating walls, enclosures and other measures which disturb the transmission path can be used to

reduce the noise exposure of the environment.

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Objective1: understanding what is a decibel scale dB, understanding how varies the noise level

for different decibel scales;

Objective 2: understanding what is the white noise; what is a bandwidth

Objective 3: what is the noise level and the noise spectrum, pick values and mediate values

E x p l a n a t i o n :

The noise is measured with a decibel scale dB. There are many different scales (the most important are

dB A and dB C) that correlate the measured sound response to the human sense of sound. The most

used filter is A, filters B and C are rarely used. Measurements made with this scales are expressed as dB

(A), dB (B), dB (C).

For generating the signal, you will use a computer (any computer that has a sound card). From the

computer the signal goes to an amplifier and then to a speaker. For the signal generation you can use

files already generated (mp3 or wav )

While the signal is generated the data acquisition will also be done. You will use the spectrometer to read

the signal. You will also visualize the signal on the spectrometer‟s display

M a t e r i a l :

computer

noise generator (speaker)

sound level meter

M a x i m u m d u r a t i o n :

60 minutes

M a i n q u e s t i o n s t o b e a s k e d :

1. What differences do they observe in the spectrum of frequencies, when they use dB(A) and

2. dB(C) filters in comparison to the situation they do not use any filter?

3. How vary the noise level for different decibel scales? dB(A) and dB(C)

4. How vary the values when they are measured as pick values and as mediate values?

5. What frequencies incorporate the white noise?

6. What is a bandwidth?

7. Which sound is more disturbing? The wide band or narrow band sound?

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I n t r o d u c t i o n / S t a r t e r s

Play a CD containing all sort of noises; noises created by different types of transportation,

electronic devices, animals, etc. Try to match them: which sound corresponds to which type of

transportation, electronic devices, animals etc...

a poster with the decibel scale and explain them the scale

OR

play some movies that we recorded using the noise acquisition system and an aeromodel, a car

etc as a noise generator.

M a i n a c t i v i t i e s

1. Turn on the noise generator (in this case the noise generator is assembly consisting of the computer,

the amplifier and the speaker) and the sound level meter.

Turn on the white noise wav file.

The noise generator will generatea signal containing all the frequencies (this is the white noise).

Ask the students to measure the noise spectrum and the sound level using the sound level meter.

The noise spectrum is represented by the sound level on every frequency.

This measurements are done for observing the dominate frequencies.

Ask them to measure the spectrum on the dB A scale and on the dB C scale (observe the differences);

this first measurement is for the pick values. The graph they will observe on the display is similar to the

one below. Ask them to write the values of the noise level for the frequencies in the table below and then

to draw a graph.

2. For the second measurement, they will measure the mediate value of the noise spectrum, also on the

dB A scale and on the dB C scale (observe the differences); the mediate value of the spectrum is done in

a period of time (few seconds) – set the period of time on the sound level meter. The graph they will

obtain on the display of the sound level meter for both measurements is called histogram. Also ask them

to make the same table using the mediate values and draw a graph.

The total noise level is the sum of all the noise level on all the frequencies (one single value). This

measurement of the noise level can be done on the dB A scale and on the dB C (observe the

differences); They will first measure the total noise level – the pick value and setting a period of time they

will measure the mediate value of the total noise level.

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It will be generated different frequencies (play the different wav files): 50Hz, 100Hz, 125Hz, 200Hz, 500

Hz, 1000Hz, 2000Hz, 4000 Hz, and 6300 Hz, 12500 Hz, 16000 Hz and the, measurements above are

repeated. Ask the students to use the table below to write down the results and draw a graph.

It will be generated a base frequency (1000 Hz) (with a wav file) and the bandwidth is modify; Using the

sound level meter, they will visualize the frequencies spectrum and the loudness.

C o n c l u s i o n / P l e n a r y

What differences do they observe in the spectrum of frequencies, when they use dB(A) and dB(C) filters?

If you use dB (A), there are certain frequencies that are attenuated compared to the use of dB(C)

How vary the noise level for different decibel scales? dB(A) ,and dB(C)

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Objective: students have to experience drag using different shapes and to deduce which one is

producing the smallest amount of drag.

E x p l a n a t i o n :

Geometry has a large effect on the amount of drag generated by an object. As with lift, the drag depends

linearly on the size of the object moving through the air. The cross-sectional shape of an object

determines the form drag created by the pressure variation around the object. The three dimensional plan

form shape affects the induced drag of a lifting wing.

To produce less drag the shape of the object has to be aerodynamic, stream lined. Think about a plane

and its form or think about a boat. Their forms are aerodynamic, they are not cubs or spheres or plates.

M a t e r i a l :

few tanks

different forms: flat plates, few bearing balls, an aerodynamic form, water,

a cube, scotch tape

M a x i m u m d u r a t i o n :

60 minutes

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M a i n q u e s t i o n s t o b e a s k e d :

What is drag?

What influences drag?

Why do you think form influences drag?

I n t r o d u c t i o n / S t a r t e r s

Ask the students what drag is. Let more of them answer and ask them to explain. Which factors do you

think influence drag? Explain. Show them the board with the forms and ask them which of the forms they

think produce less drag.

M a i n a c t i v i t i e s

Divide the students in groups of four, each group will have: one tank filled with water and few

forms: flat

plate, sphere and an aerodynamic form(we will use a boat and a wing)

Ask them to fill the tank with water, and then try to move the forms in the water using the hand.

They have

to move them horizontal and monotonous. First use the flat plate, then the sphere and then the

boat and the wing.

Ask them to write down which of this forms they could move easier.

For the second experiment we need two tanks filled with water, two identical bearing balls (having the

same size, same weight and the same roughness) and another two having different size.

In the same groups of 4, ask them that each one to drop the balls in the tanks at the same time.

Ask them to repeat this using two different sized balls

Ask them to write down their observations

C o n c l u s i o n / P l e n a r y

The smallest amount of drag is produced by an aerodynamic profile.

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Objective: experiment the viscosity of a fluid

E x p l a n a t i o n

the concept of viscosity seems well known by the students, but they will have a better understanding after

few simple experiments

M a t e r i a l :

few tanks

different forms: flat plate, few balls, an aerodynamic form, water, oil, honey, shower gel, few

cylinders

M a x i m u m d u r a t i o n :

20 minutes

M a i n q u e s t i o n s t o b e a s k e d :

Give examples of liquids more viscous than water.

How viscosity depends on temperature?

Is viscosity influencing the drag? Why is that?

I n t r o d u c t i o n / S t a r t e r s

Ask your students what is more viscose: water, oil or honey? Ask them to explain their choice.

M a i n a c t i v i t i e s

Ask the students to fill the three cylinders with water, oil and honey. After doing that ask them to open the

orifice and let the fluid flow. Ask them which of the three fluids they think is less viscose and more

viscose.

Liquids with higher viscosities will not make such a splash when poured at the same velocity.

Ask the students to fill with water and honey two tanks. Ask them to use a stick to blend the water and the

honey. Then ask them to drop an abject in each of the tanks (two identical objects). Ask them to write

their observations, which of the two fluids is more viscose and why.

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Viscosity depends on temperature, when temperature increases the viscosity tends to decrease. The

viscosity of air depends mostly on the temperature. To visualize this dependence, ask the students to

heat the honey, they will observe the change in viscosity, the heated honey will be less viscous; also they

can put the honey in the refrigerator for few minutes, and they will observe the change in viscosity, the

honey in the refrigerator will be more viscous.

Ask the students to fill with water, oil and honey three tanks and to pick a form they want and to put it first

in the tank filled with water and try to move it and then do the same in the other two tanks. Put them work

in groups of four. Ask them to write their observations.

C o n c l u s i o n / P l e n a r y

Liquids with less viscosity will not oppose to movement.

Liquids with higher viscosities will not make such a splash when drop an object in them.

Drag is influenced by the viscosity of the fluid. If the fluid is more viscose, drag is increasing,

because viscosity opposes movement.

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Objective: To demonstrate that drag is influence by the type of surface

E x p l a n a t i o n :

If we think of drag as aerodynamic friction, the amount of drag depends on the surface roughness of the

object; a smooth, waxed surface produces less drag than a roughened surface. This effect is called skin

friction and is usually included in the measured drag coefficient of the object.

Rough surface: produces a big amount of drag.

Smooth surface: the surface of a plane is very smooth and polished, producing a small amount of

drag.

M a t e r i a l :

few tanks

different forms: few flat plates, an aerodynamic form very polished

water

emery paper with different degrees of roughness

M a x i m u m d u r a t i o n :

15 minutes

M a i n q u e s t i o n s t o b e a s k e d :

Do you know how it feels when you touch the surface of a plane?

Why is the surface of the plane so smooth?

I n t r o d u c t i o n / S t a r t e r s

Ask the students if they ever touched the surface of a plane. How was the surface?

It was rough?

It was smooth?

M a i n a c t i v i t i e s

If they didn‟t touch before the surface of a plane (end even they did), ask them to touch the wing or the

aeromodel you have in the classroom. Ask them to write why they think the surface is the way it is

(smooth).

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Ask the students to glue emery paper with different degree of roughness on few plates, and then to move

them on a plain surface. What is their remark on this?

Which one they can move easier and witch one opposes the movement.

C o n c l u s i o n / P l e n a r y

We think of drag as aerodynamic friction, the amount of drag depends on the surface roughness of the

object; a smooth, waxed surface produces less drag than a roughened surface.

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Objectives: In this experiment the students will measure the drag using a dynamometer.

E x p l a n a t i o n :

Measuring the drag this way, changhing the variabiles on by one, gives them a better understanding of

drag and what are the variabiles that influence drag and what can be done to reduce drag.

M a t e r i a l :

different forms: few flat plates, cubes, an aerodynamic form very polished, emery

paper with different degrees of roughness

an aeromodel

a dynamometer

a fan

M a x i m u m d u r a t i o n :

1 hour

M a i n q u e s t i o n s t o b e a s k e d :

After doing all the previous experiments and the next experiment ask them to tell you what influences

drag and why.

I n t r o d u c t i o n / S t a r t e r s

Remind your students of session 1. Ask them to tell you which form, they think produces less drag. Ask

them to keep that in mind when they will do the following measurements.

M a i n a c t i v i t i e s

Ask the pupils to take a cube and put it on the table and to chain it with a rope like in this picture and then

ask them to hang the dynamometer from the end of the rope. Place the fan in front of the dynamometer

and start it. Ask them to write the indication of the dynamometer in a chart like the one below. Repeat the

experiment at least five times and then mediate.

Object Smooth Cube Cube having asmall degree of

roughness

Cube having a bigger degree of

roughness

1

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2

3

4

5

Mediate

Repeat the experiment using cubes with different degrees of roughness that they used at the previous

experiment. Ask them to write down the indication of the dynamometer in the same chart. What is the

conclusion?

Repeat the same experiment but instead of the cube use o ball. Ask them to make another chart and on

the first line to write the result for the first cube and in the second line to write the result for the ball.

Repeat the experiment once again this time using an aeromodel. Ask them to write the result on the third

line of the chart. What is their conclusion?

Object Smooth Cube Ball Aeromodel

1

2

3

4

5

Mediate

Repeat the same experiment using the aeromodel, but this time increase the speed of the wind. Put both

results in the same chart. What is your observation?

Aeromodel Low Speed Medium Speed Hight Speed

1

2

3

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4

5

Mediate

C o n c l u s i o n / P l e n a r y

Measuring the drag this way, changing the variables on by one, gives them a better understanding of

drag and what are the variables that influence drag.

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Objective 1: understand what flow is

Objective 2: how many types of flow exist and what is the difference between them

E x p l a n a t i o n :

A flow is the continuous movement of a fluid, either a liquid or a gas, from one place to another. The flow

can be simple and it is called laminar, and can be complicated and it is called turbulent. We will illustrate

what one and another means.

M a t e r i a l :

a faucet (if you have in the class room)

a cup

few incandescent sticks

a pencil

a cub

M a x i m u m d u r a t i o n :

10 minutes

M a i n q u e s t i o n s t o b e a s k e d :

What is flow?

How many types of flow exist?

Can you describe them?

Can you give examples?

I n t r o d u c t i o n / S t a r t e r s

Ask them what they think flow means? Show them the following pictures and ask them if they think it is a

flow.

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M a i n a c t i v i t i e s

First of all, if you have a sink in your class room, ask the students to open the faucet. At the beginning

open the faucet not too much. Ask them what they observe; haw is the flow?

Then ask them to put a cup under the flow of water. What they observe now?

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How is the flow after it hits the cup? After this simple demonstration of flow, ask the students to try a very

simple experiment to visualize the turbulent flow of the smoke generated by a perfumed stick.

Using a lighter fire the stick, and observe what is happening. Ask them how the flow is. For the first few

centimeters, the flow remains laminar, and then becomes unstable and turbulent as the rising hot air

accelerates upwards.

After that ask them to place a pen or an eraser in the smoke (in the first few centimeters when the flow is

still laminar) and observe what is happening. The smoke will avoid the obstacle and will start to flow in

very different directions and different speeds; it will be very unstable and turbulent.

C o n c l u s i o n / P l e n a r y

The flow is the continuous movement of a fluid, either a liquid or a gas, from one place to another.

Basically there exist two types of flows, namely laminar flows and turbulent flows. Roughly speaking we

can say that a laminar flow is a 'simple' flow while a turbulent flow is a 'complicated' flow.

In a laminar flow all the molecules in the fluid move more or less smoothly in the same direction and at

the same speed.

In a turbulent flow, the molecules in a fluid move in many different directions and at many different

speeds.

Turbulence is that state of fluid motion which is characterized by apparently random and chaotic three-

dimensional velocity. When turbulence is present, it usually dominates all other flow phenomena and

results in increased energy dissipation, mixing, heat transfer, and drag. If there is no three-dimensional

velocity, there is no real turbulence. The reasons for this will become clear later; but briefly, it is ability to

generate new velocity from old velocity that is essential to turbulence.

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Objective: Get a better understanding and a better visualisation of flow

E x p l a n a t i o n :

The flow can be observed better in water.Using coloured ink the students will visualize the flow

M a t e r i a l :

a tank filled with water

ink

a little bottle

some forms: a ball, a cub and an airfoil

M a x i m u m d u r a t i o n :

20 minutes

M a i n q u e s t i o n s t o b e a n s w e r e d

What do you think will happen with the ink?

M a i n a c t i v i t i e s

Fill the tank with cold water. Fill the bottle with hot water and ink. Take the bottle and place it inside the

tank on the bottom of the tank. Observe what is happening with the coloured water in the bottle. You can

put different forms into the water above the bottle and observe how the flow will go around them.

C o n c l u s i o n / P l e n a r y

The first few centimetres the flow is laminar and then it turns into turbulent flow.

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Objective1: understanding and observing how the air flows on different solid bodies

Objective2: understanding and observing the turbulent flow

E x p l a n a t i o n :

When a solid body is placed in the wind, the air will start flowing differently, creating turbulence.

Turbulence is influenced by fluid viscosity, fluid speed, geometrical obstacles that the fluid encounters in

its path. To observe how each influence the turbulences, we can modify one at a time the fluid viscosity

(use different types of smokes), modify the speed at which the fluid is flowing, and modify the geometrical

shape of the obstacle that the flow encounters in its path.

M a t e r i a l :

a fan, a smoke generator and few objects with different forms (a ball, a cub, an airfoil) and a rack for

supporting the airfoil.

M a x i m u m d u r a t i o n :

45 minutes

M a i n q u e s t i o n s t o b e a s k e d :

1. What do you think influences flow?

I n t r o d u c t i o n / S t a r t e r s

Turn on the fan and the smoke generator and ask the students to place their hands into the flow.

The degree of turbulence depends on the speed of the wind - while moving the solid block further or

closer from the smoke generator, it will encounter lower or higher speeds of the moving air/smoke (Kids

have to observe that – it can be done by placing the hand in the flow created by the fan, at different

distances from the fan, the hand will feel more or less pressure caused by the speed of the air at that

certain distance).

M a i n a c t i v i t i e s

In this first experiment, the shape of the form placed in the flow will be modified.

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Start the fan on the first speed (the lowest speed) and the smoke generator. Watch the smoke flow

generated by the fan.

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First place the ball in front of the smoke generator and the fan and observe how the smoke flows around

it. Start moving the ball by modifying the distance between it and the smoke generator and observe how

the flow changes; change the height at which the ball is placed and observe again the flow at certain

distances from the smoke generator.

Write down your observations.

If the experiment is not working properly with the fan behind the smoke generator, place the smoke

generator behind the fan and let the fan suck in all the smoke.

Repeat the same experiment this time using a cub. Write down the observations.

Repeat the same experiment this time using an airfoil. This time the aerodynamic profile will be placed

into the flow at different angles. Write down the observations.

Now put the airfoil on 0 degrees again and increase the speed (put the fan on the higher speed). Write

down the observations. Increase the speed again. Note the differences.

For the last experiment, keep the airfoil but modify the fluid viscosity (for this we will use a different type of

smoke). Observe how the viscosity influences the degree of turbulence.

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C o n c l u s i o n / P l e n a r y

The degree of turbulence depends on the speed of the wind, the viscosity of the fluid, the shape it

encounters in its path and the airfoil‟s angle of attack.

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Objective1: To give an overview of aeronautical safety technology

Objective2: To give to the students an insight on applied research on safety in aeronautical field

Explanation: The teaching materials will be utilized to give essential concepts of aeronautical safety

problems, and to see how they are managed and improved.

M a t e r i a l :

Multimedia black board + Power Point Like Software

Photos / Videos

Pictures

Materials for experimentation

M a i n a c t i v i t i e s

By utilizing the story of a flight of a group of students and teachers the Safety problem will be

introduced and safety management will be discussed

Students will be asked to give examples of safety problems in field other than aeronautics

Students will be asked to give personal experiences on safety problems

M a x i m u m d u r a t i o n :

30 minutes

M a i n q u e s t i o n t o b e a s k e d :

Ask the students which part of an airplane is important for safety

Ask the students which flight phase is more relevant for safety

Ask the student which organization are involved in the safety of the air transportation system

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Objective1: To give to the students the general concept of active safety inside the air-transport

Objective2: To show to students devices and procedures utilized to manage aeronautical active safety

Objective3: To give to the students an insight on applied research on active safety in aeronautical field

M a t e r i a l

Multimedia black board + Power Point Like Software

Photo and or videos

Figure 1 Airplane accident

Figure 2 Airplane accident

D u r a t i o n :

30 minutes

D e v e l o p i n g o f A c t i v i t y

Expose to the students the active safety problem by the story of a flight by a group of students

Show to students photos/videos of aeronautical accidents

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Show to the students photos/video of active safety research

Ask the students questions about safety in aeronautical transportation

R e s u l t s o f A c t i v i t y

Definition of Active Safety

Description of devices and procedures for aeronautical active safety

Give the students an insight about applied research in aeronautical active safety

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Objective1: To give to the students the general concept of passive safety inside the air-transport

Objective2: To show to students devices and procedures utilized to manage passive aeronautical safety

Objective3: To give to the students an insight on applied research on passive safety in aeronautic

M a t e r i a l :

Multimedia blackboard + Power Point Like Software

Photo and or videos

Materials for experimentation

D u r a t i o n :

30 minutes

D e v e l o p i n g o f A c t i v i t y

Expose to the students the passive safety problem by the story of a flight by a group of students

Show to students photos/videos aeronautical accidents

Show to the students photos/video of passive safety research

Ask the students questions about passive safety in aeronautical transportation

R e s u l t s o f A c t i v i t y

Definition of Passive Safety (Crashworthiness)

Description of devices and procedures for aeronautical passive safety

Give the students an insight about applied research in aeronautical passive safety

E x p e r i m e n t : T h e F A L L o f a g l a s s w i t h a n d w i t h o u t a c a n

Take an shatterproof glass. Make it to fall from some height. You will see it to break. Put it on the top of a

very thin aluminium can. Make them to fall again. You will see that the glass will not break anymore.

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Figure 20 glass and can

When the glass without the aluminium can falls, the kinetic energy makes it to be broken. When the glass

falls on the top of the aluminium can, the kinetic energy transforms itself into deformation energy of the

can. So the impact forces on the glass don‟t have the value to break the glass.

In a crash of an airplane, the structures, adequately designed will adsorb the vertical kinetic energy of the

airplane. So the deceleration (forces) on human body (inside) will not cause fatal or sever injuries.µ

So passengers and crew could survival even the airplane is destroyed.

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Objectives1: Give to the students an insight of forces acting of a flying airplane structures and

understand which materials have to be used to withstand those forces.

To get students to have an overview of aeronautical design criteria

Explore with students some critical structural event on in flight airplane

Give to the students an idea of applied research for this aspect of aeronautics

E x p l a n a t i o n :

The teaching materials of this sections are utilizing to give to the students the essential concepts of

aeronautical safety related to structural resistance and to show them how those problems are managed in

today air transportation and improved in applied research centers.

M a t e r i a l :

Multimedia black board + Power Point Like Software

Photos / Videos

Set of devices for experimentation

Pictures

M a i n a c t i v i t i e s

To describe to the students the most important parts of an airplane and their functions and some

aspect of related safety

To explain the change of capability in withstanding loads in relation with the status of the matter

To show the limit capability of materials to withstand loads

M a x i m u m d u r a t i o n :

2 Hours

M a i n q u e s t i o n t o b e a s k e d :

Do you know the function of the most important (external) parts of an airplane?

Can an aeronautical structure be made just of water or air?

Do the limit loads of an aeronautical structural element depend only from material property?

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E x p e r i m e n t : S o l i d s , l i q u i d s a n d g a s e s

Take a rectangular parallelepiped solid, different types of containers (at least one cylindrical) and

liquid, a closed container where can be produced a gas (burning some adequate material). Change the

position of a solid. Pure the liquid of cylindrical container in the others. Make the gas to full up all the

container.

Figure 17 Solids Liquids Gases

By calculation can be demonstrated for solid, that they maintain their form and volume. For liquid, that

they maintain volume, but they assume the container form. For gases, that they tends to full up all the

container, so they assume form and volume of the container.

Anticipate that the different behaviour or solids, liquids and gases are explained by internal matter

constitution and these differences justify the way they withstand loads.

E x p e r i m e n t : H o w s o l i d s , l i q u i d s , g a s e s w i t h s t a n d s l o a d s

Take a syringe push down the piston and then pull up it with the hole open. Closing the hole push down:

the internal air will balance your pushing force. With the hole still closed pull up the hole. No resistance

you will experience beside some friction of the piston. Full up now the syringe by water and then after the

closed hole push down the piston. You can‟t go on in pushing: the liquid balance the pushing force. Then

pull up the piston No resistance you will experience besides some piston friction.

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Take a plastic bottle, with two or three holes in the bottom. When the bottle is full up of water you can see

some water jet. By open and closing the cap, you can have or not the water jet.

Put on the parallelepiped solid different weight. The solid maintains its form.

Apply to the oblong balloons (full up of air or water) different loads. Only compression loads are balanced

by internal forces.

Figure 18 Actions on solids, liquids and gases

E x p l a n a t i o n

With simple experimentation you have remarked that liquids and gases withstand only compression

loads, otherwise solids can withstand any kind of loads.

C o n c l u s i o n / P l e n a r y

On an airplane structures acts any kind of loads. So aeronautic structures have to be equivalent to solids.

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Objectives1: To give to the students an insight in principal functions of the most important parts of an

airplane

Objectives2: To emphasize loads that each part of an airplane has to withstand to

M a t e r i a l

Multimedia blackboard + Power Point Like Software

Photos/videos

D u r a t i o n :

one hour.

Figure 3 Forces acting on aircraft

Figure 4 Wing parts

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Figure 5 Tail Parts

Figure 6 Aircraft engine

D e v e l o p i n g o f A c t i v i t y

Teach to the students the functional analysis of a complex system (an airplane)

Show to students the most important part of an airplane and their function and the related safety

problems

Make the students discuss about the arguments

C o n c l u s i o n / P l e n a r y

Explanation of the most important pats of an airplane and their functions.

Make in evidence relationship between functions and possible safety problems.

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Objectives1: To give to the students the general concept of limit loads for aeronautical structures

Objectives2: To show to students different way of structural failures

Objectives3: To give to the students an insight on design criteria of aeronautical structures applied

M a t e r i a l :

Multimedia black board + Power Point Like Software

Materials for experimentation

Photo/Videos

Pictures

D u r a t i o n :

90 minutes

D e v e l o p i n g o f A c t i v i t y

Make the students to performs experiments on static limit loads of materials

Show to students failure of aeronautical structures other than static limit loads

Explain to the students relationship between loads and deformations

Ask the students questions about the arguments

C o n c l u s i o n / P l e n a r y

Explanation of limit loads and relation to structural failures

Give an insight to design criteria and to procedures for aeronautical structures

Give the students an insight about applied research in aeronautical active

REStARTS –The Experiments

109

Objective1: Emphasise critical aspect of high altitude cruise flight: very low pressure and temperature

Objective2: Show to students how passenger and crew life can be assured in an high altitude flight

Objective3: Give examples of some critical condition and how they are managed

E x p l a n a t i o n :

The teaching materials of this section is utilizing to show how the flight at high temperature is possible for

passengers and crew lift.

M a t e r i a l :

Multimedia whit board + Power Point Like Software

Set for specific experiment

Pictures

Videos

M a i n a c t i v i t i e s

To show critical condition in a high altitude flight for an human being life

Describe system to assure passengers and crew life in a high altitude flights

How to solve some critical condition

M a x i m u m d u r a t i o n :

90 minutes

M a i n q u e s t i o n t o b e a s k e d :

Why there are low temperature and low pressure atmosphere condition in a today cruise flight

Do the previous aspects have an impact on the engine of an aircraft?

Which accident can be caused from high altitude flight?

REStARTS –The Experiments

110

Objective: Explain that a fuselage of an airplane designed to fly at high altitude, besides other loads has

to withstand a differential pressure between the external (atmosphere static) pressure and the internal

thermodynamic pressure.

E x p l a n a t i o n :

The teaching materials will utilized to give show how the fuselage skin withstand a differential pressure

M a t e r i a l :

Multimedia black board + Power Point Like Software

Photos / Videos

Pictures

Figure 7 Pressurized Fuselage

M a i n a c t i v i t i e s

By utilizing pictures (and eventually photos) and experimentations the students will learn how the

fuselage skin withstand differential pressure

Student will be asked to make a comparison with a submarine vehicle

M a x i m u m d u r a t i o n :

60 minutes

REStARTS –The Experiments

111

M a i n q u e s t i o n t o b e a s k e d :

What is the impact of fuselage capability to withstand to a differential pressure on the airplane

characteristics?

Ask to the students if they know some suggested procedures in case of a fuselage failure

D e v e l o p i n g o f A c t i v i t y

Make the students to perform experimentation

Explain to the students by pictures how a pressurized fuselage withstand the differential pressure

Make the students to discuss about this kind of problems

R e s u l t s o f A c t i v i t y

The differential pressure is balanced by internal skin capability to with stand traction loads

The differential pressure could cause a fuselage local skin failure or the doors to be open

Emergency procedures consists for pilots to get quickly a lower altitude and for passengers and

crew to use the oxygen masks

E x p e r i m e n t 1 : S t a t i c A i r p l a n e M o d e l

Take a static airplane model (as completed as possible in every its elements).

Ask the student to tell the functions of each element.

Discuss with students about forces acting on each elements.

Figure 15 Airplane Parts

REStARTS –The Experiments

112

Each part of a transport airplane has more than one function. One of the most important is: withstand

loads. The way each part is designed depends on their function and on the kind of loads they have to

withstand to.

To withstand loads is one of the most important function of an airplane element. The kind of loads

explains the choice of the material of that element.

REStARTS –The Experiments

113

Objective 1: Explain problems and solutions in case of ice conditions

Objective 2: Give an insight in the today applied research on ice problems in aeronautical field

E x p l a n a t i o n :

The teaching materials will utilized to give essential concepts of problem due to ice accretion on

an airplane surface and solutions for it.

M a t e r i a l :

Multimedia black board + Power Point Like Software

Photos / Videos

Figure 8 Ice on a model in a wind tunnel

Figure 9 Simulation model for ice problems

REStARTS –The Experiments

114

M a i n a c t i v i t i e s

By utilizing photos and eventually videos the students will learn technology concerning ice

accretion on a flying airplane

Student will be asked to figures out analogy with similar events in every day live

M a x i m u m d u r a t i o n :

60 minutes

M a i n q u e s t i o n t o b e a s k e d :

What is the impact of ice accretion on air transportation safety?

Ask to the students why high altitude clouds are not yet transformed in ice

D e v e l o p i n g o f A c t i v i t y

Explain to the students which problems ice accretions on airplane could cause

Make the students to compare ice problems in a flying airplane with every days similar problems

Make the students to figure out suggestions for solutions of the ice problem

R e s u l t s o f A c t i v i t y

To explain that ice accretion could cause stall problems, loss of controllability, engine flame out

or even engine explosion, failure on flight strumentations

To show to the students the different devices to face ice accretion

E x p e r i m e n t 2 : B o w a n d a r r o w

Make a student to lunch an arrow with a bow.

Ask the student to tell forces and deformations in each part of the system (included) the arm and

the hand of the archer.

Figure 16 Bow and arrow

REStARTS –The Experiments

115

In a system like a bow and arrow loads acts as: compression, traction, bending moment, torque moment,

etc. Each of them cause on a single system element deformation as: shortening, lengthening, bending,

etc...

The aeronautical structures are subject to different kind of loads. So they have to be designed and

manufactured so that they would be able to withstand all kind of loads.

REStARTS –The Experiments

116

Objective1: Emphasize critical condition that can occurs during take off or landing phases

Objective2: Explain the importance of the fin and the rudder for an airplane

Objective3: Show an application of passive safety (crashworthiness)

E x p l a n a t i o n :

The teaching materials of these sections are utilized to show the control capability of an airplane in the

case of one engine out or side wind in take off or landing conditions. Moreover will be shown how

crashworthiness technology can save human life or avoidsevere injuries in the case of an hard landing.

M a t e r i a l :

Multimedia whit board + Power Point Like Software

Set of devices for experimentation

Pictures

Videos

Figure 10: Take off phase

Figure 11: Landing phase

REStARTS –The Experiments

117

M a i n a c t i v i t i e s

By pictures and experiments will be shown how an airplane can flight along the run way in case of

an engine out or in the case of a strong side wind. If possible some videos will be shown of these

events.

Some videos can be shown on an emergency landing, with the crash of fuselage. A simple

experiments will be performed to show some application of crashworthiness technology

M a x i m u m d u r a t i o n :

90 minutes

M a i n q u e s t i o n t o b e a s k e d :

Is the one engine out condition more or less critical depending on the airplane configuration?

Does an airplane contrast any value of a side wind condition?

Why are the one engine out and side wind conditions less critical at high altitude?

REStARTS –The Experiments

118

Objective1: To give essential concepts of management of one engine out condition at take off and

landing phases

Objective2: To give ideas of critical potential critical problem of the above condition

Explanation:

The teaching materials will utilized to give some examples of management and critical problem of one

engine out condition in take off and landing problems

M a t e r i a l :

Multimedia black board + Power Point Like Software

Videos

Pictures

Figure 12 One engine out condition

M a i n a c t i v i t i e s

By pictures and (if possible) by videos will be explain the management and the critical problems

in the event of one engine out in take off and landing phases.

Student will be asked to think about extreme situation for this event

M a x i m u m d u r a t i o n :

30 minutes

M a i n q u e s t i o n t o b e a s k e d :

What is the most important airplane part concerning the capability of one engine out control?

REStARTS –The Experiments

119

What is the above event more critical for each airplane configuration?

D e v e l o p i n g A c t i v i t i e s

To explain that ice accretion could cause stall problems, loss of controllability, engine flame out

or even engine explosion, failure on flight instrumentations

To show to the students the different devices to face ice accretion

R e s u l t s o f A c t i v i t y

The force moment (about the Centre of Gravity) of the active propulsive force is balanced by the

aerodynamic lateral force on the vertical tail due to rudder deflection.

It is mandatory that the airplane maintains the runway direction in the take off or the landing

phase.

REStARTS –The Experiments

120

Objective1: To give essential concepts of management of side wind condition during take off and landing

phases

Objective2: To give ideas of critical potential critical problem of the above condition

E x p l a n a t i o n :

The teaching materials will utilized to give some examples of management and critical problem of side

wind condition in take off and landing phases

M a t e r i a l :

Multimedia black board + Power Point Like Software

Photos / Videos

Pictures

Figure 13 Side wind condition

M a i n a c t i v i t i e s

By pictures and (if possible) by videos will be explain the management and the critical problems

in the event of side wind in take off and landing phases.

Student will be asked to think about extreme situation for this event

M a x i m u m d u r a t i o n :

30 minutes

REStARTS –The Experiments

121

M a i n q u e s t i o n t o b e a s k e d :

What is the most important airplane part concerning the capability of side wind control?

What is the above event more critical for each airplane configuration?

D e v e l o p i n g o f A c t i v i t y

Make the students understand how is managed a wind side condition at takeoff and landing

phases

Make the students to figure out critical situations in side wind conditions in take off /landing

phases

R e s u l t s o f A c t i v i t y

The force and force moment (about the Centre of Gravity) of the aerodynamic force due to wind

side effect is balanced by the aerodynamic lateral force on the vertical tail due to rudder

deflection.

It is mandatory that the airplane maintain the runway direction during the take off or the landing phases.

Experiment: A Kid Balloon

Take a kid balloon. Blow up it until the explosion.

By blowing up a kid balloon you increase the air mass inside the balloon. For the gases lows

the(thermodynamic) inside increase its values, it overcomes the external atmospheric (static) pressure, so

the balloon tends to inflate. The thin container balance the differential pressure by its internal capability to

withstand traction loads. When the limit traction load of the thin container is reached the balloon

explodes.

Figure 19 Kid Balloon

REStARTS –The Experiments

122

A pressurized fuselage of an airplane flying at high altitude is subjected to a differential pressure

between the external atmosphere pressure (at 10000 m is about 1/3 than at sea level) and the internal

pressure (equivalent to that at 2000 m altitude). The resultant force due to this differential pressure is

balanced by the fuselage skin to withstand traction loads.

So a pressurized fuselage has to be designed to withstand the differential pressure effect besides many

others loads.

REStARTS –The Experiments

123

Objective1: To give an example of crashworthiness (passive safety)

Objective2: To show how the aeronautical technology could manage crashworthiness problems

E x p l a n a t i o n

The teaching materials will utilized to give an example of how manage a passive safety problem

M a t e r i a l

Multimedia black board + Power Point Like Software

Photos / Videos

Experiments

Figure 14 CIRA Crash Test

M a i n a c t i v i t i e s

By experimentation and pictures an example of passive safety problem will be shown and how it

could be solved

Student will be asked to talk about their knowledge on aeronautical passive safety

M a x i m u m d u r a t i o n :

30 minutes

M a i n q u e s t i o n t o b e a s k e d :

What is the impact of passive safety requirements on Air Transportation costs?

Ask the student their opinion on how important is the passive safety requirements in Air

Transport

REStARTS –The Experiments

124

D e v e l o p i n g o f A c t i v i t y

Make the students to understand by a little experiment how a crash event in landing phase could

be managed

Make the students to understand how import could be to manage passive safety on Air

Transportation

R e s u l t s o f A c t i v i t y

One way to manage passive safety is adsorbing kinetic energy by deformation of structure

There are other problems to be solved in the case of an airplane crash