various applications of fluid mechanics
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University Of Mauritius
BEng (Hons) Chemical and Environmental Engineering - E400
FLUID MECHANICS-CHE2001Y
Assignment 1: Latest applications of Fluid Mechanics in Domestic,
Agricultural, Commercial and Industrial sectors.
Name: Fanilo Antra Tia Razafindralambo
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1. Table of Contents
1.
Table of Contents ................................................................................................ 2
2. Introduction ......................................................................................................... 3
3.
Domestic applications ......................................................................................... 4
Bladeless fan .............................................................................................................................. 4
Silicon Gas turbine .................................................................................................................... 4
4.
Commercial applications ..................................................................................... 5
Transport Means ....................................................................................................................... 5
Mp3 players ............................................................................................................................... 5
Fluid Lenses ............................................................................................................................... 6
Smart fluids ............................................................................................................................... 6
Falkirk wheel ............................................................................................................................. 7
5.
Agricultural applications ..................................................................................... 7
Study of the atmosphere and oceans ....................................................................................... 7
6.
Industrial applications ......................................................................................... 8
Computational Fluid Dynamics (CFD) ................................................................................... 8
Lubricants .................................................................................................................................. 8
Exploitation of wind energy ..................................................................................................... 8
7.
Bibliography ........................................................................................................ 9
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2. Introduction
Fluid Mechanicsalong with Thermodynamicsare probably the most important fields in which
a chemical engineer should excel. The two subjects offer a broad understanding of fluids which
allows the engineer to design and control processes effectively.
Fluid dynamics forms part of our daily lives in many simple processes ranging from the action of
watering with the aid of a hose to complex tasks such as the design of hydraulic systems.
It has traditionally been applied in such areas as the design of canal, levee, and dam systems; the
design of pumps, compressors, and piping and ducting used in the water and air conditioning
systems of homes and businesses, as well as the piping systems needed in chemical plants; the
aerodynamics of automobiles and sub- and supersonic airplanes; and the development of many
different flow measurement devices such as gas pump meters.
In this document, applications of fluid mechanics in domestic, industrial, commercial and
agricultural areas will be enumerated and described from an engineering perspective briefly.
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3. Domestic applications
Bladeless fan
They were first released in early 2009 by Sir James
Dysons company. The functioning, which is rather
simple, of the fan is absolutely a marvel of fluid
mechanics. Basically, Air comes in through the pedestal
and moves up through the circular tube that functions like
a ramp, forcing the air forward. And the resulting air flow
is buffeting free, which means that it is greener that the
normal fan. It is also much less noisy than the formal one.
(Nicholson, 2013)
Silicon Gas turbine
Alan Epstein, a professor of aeronautics and
astronautics at the Massachusetts Institute of
Technology, and his team have done a lot of
research on tiny gas turbine engines made ofsilicon. ProfessorEpsteindiscovered that the
basic concepts of turbine theory apply even to his
microturbines; the fluid mechanics turns out to be
the same as that for larger engines, as long as the
passages made for gas flow are larger than about
1 m in diameter. The rotor and its airfoils are
carved out of a single wafer, as shown in the
figure. Additional plumbing and bearings are
etched onto the wafers that are to sandwich the
rotor. Combustion occurs just outside the
rotor, at the same wafer level, spinning it by
pushing on its airfoils from the outside. At more
than a million rpm, these turbines make no audible noise. Electricity will then be generated
using, for example, a tiny generator. The fuel source could be packaged with the engine or come
as a replaceable cartridge like a cigarette lighter. In terms of power density, the little engine will
easily beat batteries, with an output of somewhere between 50 and 100 watts! (Pritchard &
Leylegian, 2011)
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4. Commercial applications
Transport Means
Pio Szyjanowicz from Cosworth have developed a
supersonic vehiclethat can travel at a top speed of
1000 miles per hour. The secret of such an amazing
performance lies, not only in the engine of the car, but
mostly on its aerodynamics(on right).
The same design principles are now being used the
manufacture the newest boat, and submarines to
improve the aquadynamicsof the machines. New
airplane wing designs have also being engineered to
optimise the flight. M shape has been found to provide
stability for gliding and W configuration for high maneuverability. These made it possible for
scientists to reach difficult airspaces such a forests. (Cox, 2012)
Mp3 players
Another interesting application of FMs is probably the
inside of the famous MP3 player. The data reading
components consist of reading head mounted very
closely to a rapidly turning tiny disc ( 500 rpm). Thedisc has to be held in place so that it does not touch the
reading head. For this purpose, former players were
equipped with Ball bearings(BBs) to hold the disc.
The problem is that BBs have a lot of components and
are noisy. Fortunately, the latest music players are
supplied with Fluid Dynamics Bearings(FDBs)
which are durable, much less noisy and allow rotation
speeds exceeding 15000 rpm which make data reading
even faster! (Pritchard & Leylegian, 2011)
The picture on the right show a FBD from a Seagate drive. (Yarvin, 2011)
The FBDs are also used in gyroscopes.
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Fluid Lenses
Fluid Lenses or, liquid lenses, have humanlike properties and are used in cameras and
cellphones. The lenses is generally made up of 2 immiscible liquids. In the example below water
and oil are used. The shape of the oil drop is altered by electrowetting. Both liquids aretransparent, with different indices of refraction but exactly the same density. The cell contains
only those two liquids and this density matching makes the whole lens very stable against
mechanical shocks. The liquid lens external shape is fixed, there is no moving part: only the
internal liquids change shape. The Arctic lens is used for high performance Auto-Focus. (Berge,
2010)
Advantages:
Quick response
High reversibility
Smart fluids
Smart fluids have been developed for many commercial sectors:
i. In automobile suspension systemsto optimise motion under all terrain conditions.
ii. Newest military uniforms contain a thin layer of smart fluid that can be stiffened to
provide strength and protection.
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Falkirk wheel
Boats entering the Wheel's upper gondola are
lowered, along with the water that they float in, to
the basin below. At the same time, an equal weightrises up, lifted in the other gondola.
This works on the Archimedes principle of
displacement. That is, the mass of the boat sailing
into the gondola will displace an exactly
proportional volume of water so that the final
combination of 'boat plus water' balances the
original total mass.
Given the precise balancing of the gondolas and
this simple but clever system of cogs, a very small
amount of energy is actually then required to turn
the Wheel. In fact, it is a group of ten hydraulic
motors located within the central spine that provide
the small amount, just 1.5kWh, of electricity to
turn it! (Bellows, 2006)
5.
Agricultural applications
Study of the atmosphere and oceans
Engineers and scientists have done a lot of research to study the behavior of atmospheric fluids
in order to predict the weather or natural catastrophes. Lately, cases such as microclimates,
tornado formations and tsunamis are carefully examined due. On February 26,Professor Mark Z.
Jacobsonhave shown, using computer simulations, that offshore wind farms with thousands of
wind turbines could have sapped the power of three real-life hurricanes, significantly decreasing
their winds and accompanying storm surge, and possibly preventing billions of dollars in
damages. (Carey, 2014)
The interesting fact is that engineers could have turned a threat into a source (renewable) of
energy! And that is the purpose of a device called Vivace converter, which uses the well-known
phenomenon of vortex-induced vibrations to extract power from a flowing current. (Pritchard &
Leylegian, 2011)
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6. Industrial applications
Computational Fluid Dynamics (CFD)
Computational Fluid Dynamics is a computer aided alternative for engineers to solve fluid flow
equations. Some of the most popular are FLUENT, from ANSYS Inc. and OpenFoam. They are
also used to simulate reactions, flows and dynamics. (Pritchard & Leylegian, 2011)
The picture on the right shows the
pathlines around a Formula 1 (from
FLUENT-image courtesy of ANSYS,
Inc. 2008.)
Lubricants
Lubricants are used in machinery to reduce friction, wear and energy consumption. A good
lubricant should be
a) Keep surfaces separateunder all loads, temperatures and speeds, thus minimising
friction and wear.
b) Act as a cooling fluidremoving the heat produced by friction or from external sources.
c) Remain adequately stablein order to guarantee constant behaviour over the forecasted
useful life.
d) Protect surfacesfrom the attack of aggressive products formed during operation.
e) Fulfil detersive and dispersivefunctions in order to remove residue and debris that may
form during operation.
Lubricants should therefore be chosen wisely. (SrivaStava, 2014)
Exploitation of wind energy
Since the last decade, engineers are aware of the global warming
problem and are now moving to renewable sources of energy.
Subsequently, wind energy has been more and more used, wind
turbines have been redesigned to optimise the process.
FloDesign Wind Turbine(on right), a spin-off from theaerospace company FloDesign based in Wilbraham,
Massachusetts, is developing a prototype that, according to CEO
Stanley Kowalski III, will be up to three times more efficient than
conventional wind turbines. Theoretically conventional wind
turbines capture a maximum of 59.3 percent of the wind energy.
The new design generates as much power as a conventional wind turbine with blades twice as
big. The smaller blade size of the new design means the FloDesign Wind Turbine could be
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packed closer together than conventional turbines, increasing the amount of power that can be
generated per acre of land. Because its blades are lighter and smaller, the design starts spinning
and generating power at lower wind speeds, and it is more tolerant of unstable wind patterns,
making it excellent for windy regions where large turbines cannot be used, such as in cities.
(Pritchard & Leylegian, 2011)
7. Bibliography1) Anon., 2011.Requirements and the properties for lubricants. [Online]
Available at: http://www.eni.com/en_IT/products-services/automotive-lubricants/about-
lubricants/requirements-properties-lubricants/requirements-properties-lubricants.shtml
[Accessed 24 September 2014].
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2) Bellows, A., 2006. The Falkirk wheel. [Online]
Available at: http://www.damninteresting.com/the-falkirk-wheel/
[Accessed 24 September 2014].
3) Berge, B., 2010.Liquid lense for auto focus. [Online]
Available at:http://www.varioptic.com/media/uploads/publication/varioptic_liquid_lens_technology_2
010_12_02.pdf
[Accessed 24 September 2014].
4) Carey, B., 2014. Offshore wind farms could tame hurricanes before they reach land,
Stanford-led study says. [Online]
Available at: http://cee.stanford.edu/news-events/news/offshore-wind-farms-could-tame-
hurricanes-they-reach-land-stanford-led-study-says
[Accessed 24 September 2014].
5) Cox, C., 2012. Supersonic Car Designed to Become World's Fastest. [Online]
Available at: http://abcnewsradioonline.com/world-news/supersonic-car-designed-to-
become-worlds-fastest.html
[Accessed 24 September 2014].
6) Genuth, I., 2007.Engine on a Chip. [Online]
Available at: http://thefutureofthings.com/3063-engine-on-a-chip/
[Accessed 24 September 2014].
7) Nicholson, C., 2013.How does a Dyson Air Multiplier work?. [Online]
Available at: http://tradecc.net/abs-bladeless-fan.html
[Accessed 24 September 2014].
8) Pritchard, P. J. & Leylegian, J. C., 2011.Fox and McDonald's Introduction to Fluid
Mechanics. 8th ed. s.l.:John Wiley & Sons, Inc..
9) SrivaStava, S. P., 2014.Developments in lubricant technology.New Jersey: John Wiley
& Sons, Inc..
10)Yarvin, N., 2011. Usenet Archives. [Online]
Available at: http://yarchive.net/blog/computers/computer_fan_bearings.html
[Accessed 25 September 2014].