AER 101 Introduction to AeronauticsInstructor : Prof. Dr. Galal Bahgat Salem

Textbook : John D. Anderson, Jr, Introduction to Flight , 4th Edition , 2000 .Term Work : 25 +25 = 50 MarksFinal Exam: 50 +50 = 100 Marks

Prof. Galal Bahgat Salem Aerospace Dept., Cairo University

AER 101 A Introduction to Aeronautics ( 2 + 1 )History of FlightNature of Aerodynamic ForcesAirplane components and ConfigurationsScope of Aeronautical EngineeringFluid Properties and CharacteristicsAtmosphereBasic Aerodynamics : Kinematics, Continuity and Bernoullis Equations, Boundary Layer Concept, Skin Friction, Pressure Drag, Flow Separation, Streamlining

Prof. Galal Bahgat Salem Aerospace Dept., Cairo University

AER 101B Introduction to Aeronautics ( 2 + 1 )Geometric and Aerodynamic Characteristics of AirfoilsDimensional Analysis and Aerodynamic Force CoefficientsElements of Airplane Performance: Drag-Speed Curve, Cruising Flight Performance, Climbing Performance, Gliding PerformanceElements of Propulsion: Propellers, Piston Engines, Reaction Principle, Jet Engines, Rocket MotorsElements of Airplane Stability and Control

Prof. Galal Bahgat Salem Aerospace Dept., Cairo University

Chapter 1History Of FlightWhat is Flight ? Flight is a motion in air free from ground topography It is a high-speed motion through a low-resistance ( low density ) medium which is airN.B. Compare flight in air, having a density of 1.225 Kg/m3, with shipping in water of density 1000 Kg/m3

Prof. Galal Bahgat Salem Aerospace Dept., Cairo University

Short History of Flight1. Imitating BirdsPeople attempting to fly by using artificial wings strapped to their arms and-or legsThe flapping of wings generate liftThe Greek myth of Daedalus and his son Icarus imprisoned on the island of Crete in the Mediterranean Sea illustrates mans flightThe idea of strapping a pair of wings to arms fell out of favorIt was replaced by concept of wings flapped up and down by various mechanical devices,

Prof. Galal Bahgat Salem Aerospace Dept., Cairo University

Powered by human arm, leg, or body movementThese are called Ornithopters Ornithopters first designed by Leonardo da Vinci ( 1452-1519 )

Prof. Galal Bahgat Salem Aerospace Dept., Cairo University

Leonardo da Vinci

Prof. Galal Bahgat Salem Aerospace Dept., Cairo University

Why Dont Ornithopters Work? G. A. Borelli (1680 ) realized the fact that ( power/weight) ratio of a man is much less than that of birdHence man will never be able to fly like a bird, by his own power only2. Lighter-than-Air Balloons[Unpowered Flight] Firstly hot air balloons discovered by the Montgolfier Brothers in France (1783)

Prof. Galal Bahgat Salem Aerospace Dept., Cairo University

Later on gas balloons of Hydrogen/Helium were used by CharlesCharles found that ballooning is based on Archimedes principle of buoyancyUnmanned Balloon Manned Balloon

Prof. Galal Bahgat Salem Aerospace Dept., Cairo University

3. Lighter-than-Air Dirigibles (Airships)[Powered]Firstly invented by Count von Zeppelin in Germany (1900) They are more rigid (the first airframe) than balloons, controlled and directed (using stabilizing surfaces) and propeller droved Large bags of gas inside the rigid airframeCount von Zeppelin (1929), flew around the world in 21 daysHydrogen fired in Hindenburg dirigible in 1937

Prof. Galal Bahgat Salem Aerospace Dept., Cairo University

Prof. Galal Bahgat Salem Aerospace Dept., Cairo University

4.Sir George Cayley (1799) First pioneered the concept for the modern airplane configuration in 1799 - Fixed wings, tail, fuselage - Separate mechanism for propulsion separation of lift and propulsion Recognized that the function of thrust was to overcome aerodynamic drag Drew the first lift-drag vector diagram in the historyN.B. Before this time flapping wings were supposed to provide both lift and propulsion

Prof. Galal Bahgat Salem Aerospace Dept., Cairo University

Prof. Galal Bahgat Salem Aerospace Dept., Cairo University

Lift Resultant Aerodynamic Force Drag Thrust

Prof. Galal Bahgat Salem Aerospace Dept., Cairo University

5.Heavier-than-Air Unpowered Gliders (Sailplanes)Gliders first designed and flew by Otto Lilienthal, a German mechanical engineer, in 1891Lilienthal is known as the gliders manGliders characterized by un-sustained flight

Prof. Galal Bahgat Salem Aerospace Dept., Cairo University

He died in 1896, after stalling a glider he was flying

Prof. Galal Bahgat Salem Aerospace Dept., Cairo University

6.Heavier-than-Air Powered AirplanesSamuel P. Langley was contracted to build a flying machine for the U.S. governmentBegan a series of aerodynamic experiments in 1887Successful in flying several small scale, unmanned, powered aircraft, which he called aerodromesThese were the first steam-powered, heavier-than-air machines to successfully flyLangleys attempt to build a manned aerodrome failedLunched and crashed on Oct. 7 and December 8, 1903

Prof. Galal Bahgat Salem Aerospace Dept., Cairo University

Prof. Galal Bahgat Salem Aerospace Dept., Cairo University

Langleys aerodrome shortly after launch

Prof. Galal Bahgat Salem Aerospace Dept., Cairo University

The Wright Brothers Wright brothers (Orville&Wilbur) were the inventors of the first practical manned flight on 17 Dec.,1903 (Flyer I )It was a strut-and-wire biplane configurationPropulsion was achieved by a four-cylinder in-line engine designed and built by Orville WrightIt produced close to 12 hp and weighed 140 IbsIt drove two propellers via a bicycle-like chain loop

Prof. Galal Bahgat Salem Aerospace Dept., Cairo University

The control feature of Wright flyer is one of the basic reasons for its successFlyer I had a wing span of 12 m , flew a distance of 256 m, and lasting 59 sec Wright Flyer Engine

Prof. Galal Bahgat Salem Aerospace Dept., Cairo University

Wright Flyer engine

Prof. Galal Bahgat Salem Aerospace Dept., Cairo University

Prof. Galal Bahgat Salem Aerospace Dept., Cairo University

Prof. Galal Bahgat Salem Aerospace Dept., Cairo University

Prof. Galal Bahgat Salem Aerospace Dept., Cairo University

Hydrostatics of Lighter-than-Air Flight The lifting force is the buoyancy forceThe basic laws of hydrostatics (fluid at rest) are: a- fluid pressure p is uniform in horizontal planes, as well as the density b- p varies only with height z according to the Hydrostatic equation z datum

Prof. Galal Bahgat Salem Aerospace Dept., Cairo University

dp/dz = -g Integrating, in case of constant density: p + g z = constant This is the hydrostatic equation non-uniform p distribution on a body immersed in a fluid at rest p p + g z z B

Prof. Galal Bahgat Salem Aerospace Dept., Cairo University

The resultant fluid-pressure force is called the buoyancy force B, acting vertically upward, and equals to the weight of the displaced fluid B = g V where density of fluid g acceleration of gravity V volume of immersed bodyN.B. The basis of Heavier-than-air Flight will discussed later

Prof. Galal Bahgat Salem Aerospace Dept., Cairo University

Anatomy OF THE AIRPLANE

The Main Components of the Airplane

Prof. Galal Bahgat Salem Aerospace Dept., Cairo University

Prof. Galal Bahgat Salem Aerospace Dept., Cairo University

Prof. Galal Bahgat Salem Aerospace Dept., Cairo University

The basic airplane components include: fuselage, wing, tail assembly, control surfaces, landing gear, and power plant(s)1.The Fuselage It carries the payload. It is the central structural member of the airframe to which other members are attached. It is generally streamlined to reduce drag. Designs vary with the mission to be performed, as illustrated in figure

Prof. Galal Bahgat Salem Aerospace Dept., Cairo University

Prof. Galal Bahgat Salem Aerospace Dept., Cairo University

2.The Wing It generates the lift force. It includes the flaps for lift augmentation during landing and takeoff, and ailerons for banking the airplane during turning.The wing cross-section is called AirfoilThe airfoil shape, wing planform shape, and placement of the wing on the fuselage depend upon the airplane mission.The figure illustrates wing shapes and placements

Prof. Galal Bahgat Salem Aerospace Dept., Cairo University

Prof. Galal Bahgat Salem Aerospace Dept., Cairo University

Prof. Galal Bahgat Salem Aerospace Dept., Cairo University

Prof. Galal Bahgat Salem Aerospace Dept., Cairo University

Prof. Galal Bahgat Salem Aerospace Dept., Cairo University

Prof. Galal Bahgat Salem Aerospace Dept., Cairo University

3.Tail Assembly and Control Surfaces

The tail assembly (empennage) represents the collection of structures at the rear of the airplaneThe tail assembly consists of: 1- The vertical stabilizer (fin) and rudder which provide directional stability in yaw 2-The horizontal stabilizer and elevator which provide longitudinal stability in pitch The figure illustrates different forms of tail assembly

Prof. Galal Bahgat Salem Aerospace Dept., Cairo University

Prof. Galal Bahgat Salem Aerospace Dept., Cairo University

4.Landing GearThe landing gear (undercarriage) supports the airplane while it is at rest on the ground and during the takeoff and landingThe gear may be fixed or retractableThe wheels are attached to shock-absorbing struts that use oil or air to cushion the blow of landingSpecial types of landing gear include skids for snow and floats for waterFor carrier landings, arrester hooks are used

Prof. Galal Bahgat Salem Aerospace Dept., Cairo University

Prof. Galal Bahgat Salem Aerospace Dept., Cairo University

4.Power PlantsPower plants used to produce the thrust force necessary to propel the airplane to overcome the dragThe power plant consists of the engine (and propeller, if present) and accessoriesThe main engine types are: -Reciprocating (or piston type) -Reaction engines such as turbojet, turbofan, turboprop, ram jet, pulse jet, and rocket engine The figure shows several some of engine placements

Prof. Galal Bahgat Salem Aerospace Dept., Cairo University

Prof. Galal Bahgat Salem Aerospace Dept., Cairo University

The Aircraft StructureThe figure shows a cutaway drawing of an aircraft structure

Prof. Galal Bahgat Salem Aerospace Dept., Cairo University

Basic Elements of Aircraft StructureThe wing

Prof. Galal Bahgat Salem Aerospace Dept., Cairo University

Wing structure basically same in all aircraft types Modern aircrafts have all metal and composite material wings but many older had wood and fabric wingsThe wing is a framework composed of spars, ribs and (possibly) stringers (see figure)Spars are the main members of the wing. They extended lengthwise of the wing (crosswise of fuselage)Most wing structures have two spars, the front spar and the rear spar

Prof. Galal Bahgat Salem Aerospace Dept., Cairo University

Front spar near the leading edge, while the rear spar at about two-thirds the distance to the trailing edgeThe ribs are the parts of the wing which support the covering and provide the airfoil shapeA skin covers the wing framework

Prof. Galal Bahgat Salem Aerospace Dept., Cairo University

The Fuselage

Prof. Galal Bahgat Salem Aerospace Dept., Cairo University

Prof. Galal Bahgat Salem Aerospace Dept., Cairo University

The fuselage structural elements are: 1-Bulkheads, which form the cross-sectional shape of the fuselage 2-Longerons, which are heavy strips that run the length of the fuselage and are attached to the outer edge of the bulkheads 3-Fuselage skin, which is attached to the longeronsN.B. Keelson is a strong beam placed at the bottom of the fuselage. The keelson is frequently used in military fighter aircrafts

Prof. Galal Bahgat Salem Aerospace Dept., Cairo University

Aerodynamic Basis of Heavier-than-Air FlightThis is the real flightIt needs a lifting force to balance the weight; since the buoyancy force is not sufficientThe source of the lifting force is the fact that when a fluid is in motion, its pressure varies not only with height, as in the case of rest, but also with its velocityThe relation between p, V, and z is expressed by Bernoulli equation (1738) :

Prof. Galal Bahgat Salem Aerospace Dept., Cairo University

p + (1/2) V2 + gz = constantWhere p static pressure (1/2) V2 dynamic pressure g z head pressure The shape of an airplane-wing cross section (known as aerofoil or airfoil) was evolved from the Venturi tube, as shown :

Prof. Galal Bahgat Salem Aerospace Dept., Cairo University

Prof. Galal Bahgat Salem Aerospace Dept., Cairo University

Prof. Galal Bahgat Salem Aerospace Dept., Cairo University

Prof. Galal Bahgat Salem Aerospace Dept., Cairo University

Prof. Galal Bahgat Salem Aerospace Dept., Cairo University

Prof. Galal Bahgat Salem Aerospace Dept., Cairo University

When a fluid flows over a body (or a surface), or when a body is forced to move through a fluid, the fluid velocity relative to the body surface may be increased or decreased (depending on surface shape and altitude)And consequently the fluid pressure p may decrease or increase according to Bernoullis equation The resultant will be a net fluid force F acting on the body which is completely different than the Buoyancy force (and may be many times greater than it)

Prof. Galal Bahgat Salem Aerospace Dept., Cairo University

Prof. Galal Bahgat Salem Aerospace Dept., Cairo University

How does an Airplane fly?The key to the generation of lift is the specially-designed streamlined body, called the wing, and characterized by a special cross-section, called airfoilWhen the wing is propelled through air at a suitable angle of attack, and with a relatively-high speed, the air flowing around its surface is accelerated and/or decelerated according to Bernoullis equation The integration of the air-pressure distribution over the surface of the wing results in a resultant aerodynamic force F

Prof. Galal Bahgat Salem Aerospace Dept., Cairo University

The component of R perpendicular to flight direction (direction of relative motion) is called the Lift LThe component of R opposite to flight direction is called drag D

Prof. Galal Bahgat Salem Aerospace Dept., Cairo University

Forces on an AirplaneBasically, the four forces acting on an airplane are weight, thrust, lift, and drag

Prof. Galal Bahgat Salem Aerospace Dept., Cairo University

Prof. Galal Bahgat Salem Aerospace Dept., Cairo University

Weight: The weight includes the airplane itself, the payload, and the fuel. Since the fuel is consumed as the airplane flies, the weight decreases. Weight acts in a direction towards the center of the Earth.Thrust: The driving force of whatever propulsive system is used, engine driven propeller, jet engine, rocket engine, and so forth, is the thrust. It may be taken to act along the longitudinal axis of the airplane.Lift: This force is generated by the flow of air around the airplane, the major portion resulting from the wing. It represents the component of the resultant aerodynamic force normal to the flight direction.

Prof. Galal Bahgat Salem Aerospace Dept., Cairo University

Drag: This force arises from the flow of air around the airplane and is the component of the resultant aerodynamic force opposite to the flight direction For un-accelerated (Steady) level flight: L = W T = D

Prof. Galal Bahgat Salem Aerospace Dept., Cairo University

Scope of Aerospace EngineeringAerospace engineering means airplane, missiles (Rockets), and satellite design, manufacturing, testing, maintaining, repairing, overhauling, and performance analysis The Main Topics A.E. are: (1) Aerodynamics (2) Airframe Design (3) Propulsion (4) Flight Mechanics & Control

Prof. Galal Bahgat Salem Aerospace Dept., Cairo University

The Associated Topics are: Flight navigation Electronics ( + Flight navigation = Avionics ) Meteorology Metallurgy Production Engineering Fluid-power engineering (pneumatic, hydraulic, pressurization, and air-conditioning systems) Instrumentation Chemical & fuel engineering Flight regulations & Airworthiness

Prof. Galal Bahgat Salem Aerospace Dept., Cairo University

The Associated Topics are: Flight navigation Electronics ( + Flight navigation = Avionics ) Meteorology Metallurgy Production Engineering Fluid-power engineering (pneumatic, hydraulic, pressurization, and air-conditioning systems) Instrumentation Chemical & fuel engineering Flight regulations & Airworthiness

Prof. Galal Bahgat Salem Aerospace Dept., Cairo University

AerodynamicsAerodynamic design of the flight vehicle/space vehicle for: Maximum lift production Minimum drag Max. available space for structure and payloadDetermination of the aerodynamic forces on the designed configuration at the different flight conditions (speed, attitude, and a altitude) Wind-tunnel testingFlight testing

Prof. Galal Bahgat Salem Aerospace Dept., Cairo University

PropulsionPower-plant design & construction for: Max. thrust/weight of engine Max. thrust/drag of engine Min. specific fuel consumption (sfc) Good performance at different altitudes and speeds of flightPower-plant manufacturingPower-plant testing

Prof. Galal Bahgat Salem Aerospace Dept., Cairo University

Airframe DesignStructural analysisAirframe design & construction for: sufficient strength and with less weightAirframe manufacturing techniquesAirframe testing techniques

Prof. Galal Bahgat Salem Aerospace Dept., Cairo University

Flight Mechanics & ControlStabilizing and control surfaces designControl surfaces operation and performanceAircraft stability analysisManeuverability considerationsAirplane systems and instrumentation

Prof. Galal Bahgat Salem Aerospace Dept., Cairo University