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Transcript of Introduction to Aerodynamics Let’s keep it simple, shall we? Why is it important and how does it...
![Page 1: Introduction to Aerodynamics Let’s keep it simple, shall we? Why is it important and how does it affect my car? Greenpower schools education event Castle.](https://reader035.fdocuments.in/reader035/viewer/2022081519/56649cfd5503460f949cdef6/html5/thumbnails/1.jpg)
Introduction to AerodynamicsLet’s keep it simple, shall we?
Why is it important and how does it affect my car?
Greenpower schools education eventCastle Bromwich Manufacturing Facility1st May 2013
Edward Sorby
![Page 2: Introduction to Aerodynamics Let’s keep it simple, shall we? Why is it important and how does it affect my car? Greenpower schools education event Castle.](https://reader035.fdocuments.in/reader035/viewer/2022081519/56649cfd5503460f949cdef6/html5/thumbnails/2.jpg)
2
Contents
• What is aerodynamics?
• So where do the forces come from?
• Why is aerodynamics so important in the design of a Greenpower racer?
• How can I make my car faster?!
http://www.listofcarbrands.com/wp-content/uploads/2012/02/pagani-zonda-f-wind-tunnel.jpg
![Page 3: Introduction to Aerodynamics Let’s keep it simple, shall we? Why is it important and how does it affect my car? Greenpower schools education event Castle.](https://reader035.fdocuments.in/reader035/viewer/2022081519/56649cfd5503460f949cdef6/html5/thumbnails/3.jpg)
3
Contents
• What is aerodynamics?
• Why is aerodynamics so important in the design of a Greenpower racer?
• So where do the forces come from?
• How can I make my car faster?!
![Page 4: Introduction to Aerodynamics Let’s keep it simple, shall we? Why is it important and how does it affect my car? Greenpower schools education event Castle.](https://reader035.fdocuments.in/reader035/viewer/2022081519/56649cfd5503460f949cdef6/html5/thumbnails/4.jpg)
4
Contents
• What is aerodynamics?
• Why is aerodynamics so important in the design of a Greenpower racer?
• So where do the forces come from?
• How can I make my car faster?!
Force on air Reaction on wall
![Page 5: Introduction to Aerodynamics Let’s keep it simple, shall we? Why is it important and how does it affect my car? Greenpower schools education event Castle.](https://reader035.fdocuments.in/reader035/viewer/2022081519/56649cfd5503460f949cdef6/html5/thumbnails/5.jpg)
5
Contents
• What is aerodynamics?
• Why is aerodynamics so important in the design of a Greenpower racer?
• So where do the forces come from?
• How can I make my car faster?!
http://enterprisezones.communities.gov.uk/wp-content/uploads/2013/03/bloodhound.jpg
![Page 6: Introduction to Aerodynamics Let’s keep it simple, shall we? Why is it important and how does it affect my car? Greenpower schools education event Castle.](https://reader035.fdocuments.in/reader035/viewer/2022081519/56649cfd5503460f949cdef6/html5/thumbnails/6.jpg)
6
WHAT IS AERODYNAMICS?
![Page 7: Introduction to Aerodynamics Let’s keep it simple, shall we? Why is it important and how does it affect my car? Greenpower schools education event Castle.](https://reader035.fdocuments.in/reader035/viewer/2022081519/56649cfd5503460f949cdef6/html5/thumbnails/7.jpg)
7
What is aerodynamics?
• Definition:> “The study of the properties of moving air and the interaction between the air and solid
bodies moving through it”
• But what does that really mean?!
http://www.listofcarbrands.com/wp-content/uploads/2012/02/pagani-zonda-f-wind-tunnel.jpg
![Page 8: Introduction to Aerodynamics Let’s keep it simple, shall we? Why is it important and how does it affect my car? Greenpower schools education event Castle.](https://reader035.fdocuments.in/reader035/viewer/2022081519/56649cfd5503460f949cdef6/html5/thumbnails/8.jpg)
8
What is aerodynamics?
• Definition:> “The study of the properties of moving air and the interaction between the air and solid
bodies moving through it”
• But what does that really mean?!
http://www.listofcarbrands.com/wp-content/uploads/2012/02/pagani-zonda-f-wind-tunnel.jpg
![Page 9: Introduction to Aerodynamics Let’s keep it simple, shall we? Why is it important and how does it affect my car? Greenpower schools education event Castle.](https://reader035.fdocuments.in/reader035/viewer/2022081519/56649cfd5503460f949cdef6/html5/thumbnails/9.jpg)
9
WHY IS AERODYNAMICS SO IMPORTANT IN THE DESIGN OF A GREENPOWER RACER?
![Page 10: Introduction to Aerodynamics Let’s keep it simple, shall we? Why is it important and how does it affect my car? Greenpower schools education event Castle.](https://reader035.fdocuments.in/reader035/viewer/2022081519/56649cfd5503460f949cdef6/html5/thumbnails/10.jpg)
10
Why is aerodynamics so important in the design of a Greenpower racer?
• In a race you have to work against 3 sources of resistance :
> Aerodynamics> We will discuss where these forces come from> Approximately 40% of the total
> Rolling Resistance> Primary cause is the rubber tyre compound deforming at the contact patch (with
ground). Some of the energy required to deform the tyre is lost as heat; a process called hysteresis. The process is continuous as the tyre rolls.
> A small component of rolling resistance is from bearings and other mechanical parts.> Approximately 30% of the total
> Mass> Uses energy to accelerate the car, or go up hills. > Rolling resistance goes up with mass as deformation of tyre at contact patch increases> Approximately 30% of the total
![Page 11: Introduction to Aerodynamics Let’s keep it simple, shall we? Why is it important and how does it affect my car? Greenpower schools education event Castle.](https://reader035.fdocuments.in/reader035/viewer/2022081519/56649cfd5503460f949cdef6/html5/thumbnails/11.jpg)
11
Why is aerodynamics so important in the design of a Greenpower racer?
• In a race you have to work against 3 sources of resistance :
> Aerodynamics> We will discuss where these forces come from> Approximately 40% of the total
> Rolling Resistance> Primary cause is the rubber tyre compound deforming at the contact patch (with
ground). Some of the energy required to deform the tyre is lost as heat; a process called hysteresis. The process is continuous as the tyre rolls.
> A small component of rolling resistance is from bearings and other mechanical parts.> Approximately 30% of the total
> Mass> Uses energy to accelerate the car, or go up hills. > Rolling resistance goes up with mass as deformation of tyre at contact patch increases> Approximately 30% of the total
![Page 12: Introduction to Aerodynamics Let’s keep it simple, shall we? Why is it important and how does it affect my car? Greenpower schools education event Castle.](https://reader035.fdocuments.in/reader035/viewer/2022081519/56649cfd5503460f949cdef6/html5/thumbnails/12.jpg)
12
Why is aerodynamics so important in the design of a Greenpower racer?
• In a race you have to work against 3 sources of resistance :
> Aerodynamics> We will discuss where these forces come from> Approximately 40% of the total
> Rolling Resistance> Primary cause is the rubber tyre compound deforming at the contact patch (with
ground). Some of the energy required to deform the tyre is lost as heat; a process called hysteresis. The process is continuous as the tyre rolls.
> A small component of rolling resistance is from bearings and other mechanical parts.> Approximately 30% of the total
> Mass> Uses energy to accelerate the car, or go up hills. > Rolling resistance goes up with mass as deformation of tyre at contact patch increases> Approximately 30% of the total
![Page 13: Introduction to Aerodynamics Let’s keep it simple, shall we? Why is it important and how does it affect my car? Greenpower schools education event Castle.](https://reader035.fdocuments.in/reader035/viewer/2022081519/56649cfd5503460f949cdef6/html5/thumbnails/13.jpg)
13
Why is aerodynamics so important in the design of a Greenpower racer?
• In a race you have to work against 3 sources of resistance :
> Aerodynamics> We will discuss where these forces come from> Approximately 40% of the total
> Rolling Resistance> Primary cause is the rubber tyre compound deforming at the contact patch (with
ground). Some of the energy required to deform the tyre is lost as heat; a process called hysteresis. The process is continuous as the tyre rolls.
> A small component of rolling resistance is from bearings and other mechanical parts.> Approximately 30% of the total
> Mass> Uses energy to accelerate the car, or go up hills. > Rolling resistance goes up with mass as deformation of tyre at contact patch increases> Approximately 30% of the total
![Page 14: Introduction to Aerodynamics Let’s keep it simple, shall we? Why is it important and how does it affect my car? Greenpower schools education event Castle.](https://reader035.fdocuments.in/reader035/viewer/2022081519/56649cfd5503460f949cdef6/html5/thumbnails/14.jpg)
14
Why is aerodynamics so important in the design of a Greenpower racer?
• To go faster, we must make each of these 3 things better
• We can do this by being clever when we design the car> This is free, and just requires some creative thinking> This is the fun way to do it!
• We can also go to the shop and buy better parts> This can get expensive> Also is time consuming, requires lots of testing and is very boring!
![Page 15: Introduction to Aerodynamics Let’s keep it simple, shall we? Why is it important and how does it affect my car? Greenpower schools education event Castle.](https://reader035.fdocuments.in/reader035/viewer/2022081519/56649cfd5503460f949cdef6/html5/thumbnails/15.jpg)
15
Why is aerodynamics so important in the design of a Greenpower racer?
• To go faster, we must make each of these 3 things better
• We can do this by being clever when we design the car> This is free, and just requires some creative thinking> This is the fun way to do it!
• We can also go to the shop and buy better parts> This can get expensive> Also is time consuming, requires lots of testing and is very boring!
![Page 16: Introduction to Aerodynamics Let’s keep it simple, shall we? Why is it important and how does it affect my car? Greenpower schools education event Castle.](https://reader035.fdocuments.in/reader035/viewer/2022081519/56649cfd5503460f949cdef6/html5/thumbnails/16.jpg)
16
Why is aerodynamics so important in the design of a Greenpower racer?
• To go faster, we must make each of these 3 things better
• We can do this by being clever when we design the car> This is free, and just requires some creative thinking> This is the fun way to do it!
• We can also go to the shop and buy better parts> This can get expensive…> …and is very boring!
![Page 17: Introduction to Aerodynamics Let’s keep it simple, shall we? Why is it important and how does it affect my car? Greenpower schools education event Castle.](https://reader035.fdocuments.in/reader035/viewer/2022081519/56649cfd5503460f949cdef6/html5/thumbnails/17.jpg)
17
Why is aerodynamics so important in the design of a Greenpower racer?
• Improving mass
• To make the car lighter, we can go from something like this> Heavy, using cheap materials and designed to be
stronger than it needs to be!
http://upload.wikimedia.org/wikipedia/commons/b/ba/1965_Turin_Salon_Miura_Chassis_-1.jpg
![Page 18: Introduction to Aerodynamics Let’s keep it simple, shall we? Why is it important and how does it affect my car? Greenpower schools education event Castle.](https://reader035.fdocuments.in/reader035/viewer/2022081519/56649cfd5503460f949cdef6/html5/thumbnails/18.jpg)
18
Why is aerodynamics so important in the design of a Greenpower racer?
• Improving mass
• To make the car lighter, we can go from something like this> Heavy, using cheap materials and designed to be
stronger than it needs to be!
• To something like this> Light, expensive
materials, welldesigned
• To make you car light and safe needs a lot of engineering know-how, exotic materials, or both!
http://upload.wikimedia.org/wikipedia/commons/b/ba/1965_Turin_Salon_Miura_Chassis_-1.jpg
http://www.zolfe.com/Images/Zolfe_chassis.gif
![Page 19: Introduction to Aerodynamics Let’s keep it simple, shall we? Why is it important and how does it affect my car? Greenpower schools education event Castle.](https://reader035.fdocuments.in/reader035/viewer/2022081519/56649cfd5503460f949cdef6/html5/thumbnails/19.jpg)
19
Why is aerodynamics so important in the design of a Greenpower racer?
• Improving Rolling Resistance
• Friction is mostly due to the components you use…> Tyres> Bearings> Chain> Gears
• Improving it requires you to buy better components!
![Page 20: Introduction to Aerodynamics Let’s keep it simple, shall we? Why is it important and how does it affect my car? Greenpower schools education event Castle.](https://reader035.fdocuments.in/reader035/viewer/2022081519/56649cfd5503460f949cdef6/html5/thumbnails/20.jpg)
20
Why is aerodynamics so important in the design of a Greenpower racer?
• Improving aerodynamics
• We want to go from this
http://cdn.speedhunters.com/wp-content/uploads/2012/05/desktop1.jpg
![Page 21: Introduction to Aerodynamics Let’s keep it simple, shall we? Why is it important and how does it affect my car? Greenpower schools education event Castle.](https://reader035.fdocuments.in/reader035/viewer/2022081519/56649cfd5503460f949cdef6/html5/thumbnails/21.jpg)
21
Why is aerodynamics so important in the design of a Greenpower racer?
• Improving aerodynamics
• We want to go from this to this
• Within the rules of Greenpower, improving aerodynamics is down to your design
• You can improve this just by being creative and clever when you design you car!
• It is therefore the cheapest and easiest way to make your car faster!
http://cdn.speedhunters.com/wp-content/uploads/2012/05/desktop1.jpg
http://www.jaguar.com/content/global/Assets_12MY/Nameplate/xf/Exterior/LHD_EU_ROW/A6_LHD_XF_12MY_012_046_Polaris_White-1008x567.jpg
![Page 22: Introduction to Aerodynamics Let’s keep it simple, shall we? Why is it important and how does it affect my car? Greenpower schools education event Castle.](https://reader035.fdocuments.in/reader035/viewer/2022081519/56649cfd5503460f949cdef6/html5/thumbnails/22.jpg)
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SO WHERE DO THE FORCES COME FROM?
![Page 23: Introduction to Aerodynamics Let’s keep it simple, shall we? Why is it important and how does it affect my car? Greenpower schools education event Castle.](https://reader035.fdocuments.in/reader035/viewer/2022081519/56649cfd5503460f949cdef6/html5/thumbnails/23.jpg)
23
So where do the forces come from?
• There are 2 main reasons why the air creates forces:
> Friction drag> Most important for very aerodynamic shapes like aeroplane wings
> Pressure drag> Most important on blunt shapes like cars
High pressureLow pressure
![Page 24: Introduction to Aerodynamics Let’s keep it simple, shall we? Why is it important and how does it affect my car? Greenpower schools education event Castle.](https://reader035.fdocuments.in/reader035/viewer/2022081519/56649cfd5503460f949cdef6/html5/thumbnails/24.jpg)
24
So where do the forces come from?
• There are 2 main reasons why the air creates forces:
> Friction drag> Most important for very aerodynamic shapes like aeroplane wings
> Pressure drag> Most important on blunt shapes like cars
High pressureLow pressure
![Page 25: Introduction to Aerodynamics Let’s keep it simple, shall we? Why is it important and how does it affect my car? Greenpower schools education event Castle.](https://reader035.fdocuments.in/reader035/viewer/2022081519/56649cfd5503460f949cdef6/html5/thumbnails/25.jpg)
25
So where do the forces come from?
• There are 2 main reasons why the air creates forces:
> Skin friction drag> Most important for very aerodynamic shapes like aeroplane wings
> Pressure drag> Most important on blunt shapes like cars
High pressureLow pressure
![Page 26: Introduction to Aerodynamics Let’s keep it simple, shall we? Why is it important and how does it affect my car? Greenpower schools education event Castle.](https://reader035.fdocuments.in/reader035/viewer/2022081519/56649cfd5503460f949cdef6/html5/thumbnails/26.jpg)
26
So where do the forces come from?A simple explanation…
• So what is pressure?> The force created when air particles bounce off things
• More air particles?> Higher pressure > bigger force
• Fewer air particles?> Lower pressure > less force
Force on air Reaction on wall
![Page 27: Introduction to Aerodynamics Let’s keep it simple, shall we? Why is it important and how does it affect my car? Greenpower schools education event Castle.](https://reader035.fdocuments.in/reader035/viewer/2022081519/56649cfd5503460f949cdef6/html5/thumbnails/27.jpg)
27
So where do the forces come from?A simple explanation…
• So what is pressure?> The force created when air particles bounce off things
• More air particles?> Higher pressure > bigger force
• Fewer air particles?> Lower pressure > less force
Force on air Reaction on wall
![Page 28: Introduction to Aerodynamics Let’s keep it simple, shall we? Why is it important and how does it affect my car? Greenpower schools education event Castle.](https://reader035.fdocuments.in/reader035/viewer/2022081519/56649cfd5503460f949cdef6/html5/thumbnails/28.jpg)
28
So where do the forces come from?A simple explanation…
• So what is pressure?> The force created when air particles bounce off things
• More air particles?> Higher pressure…bigger force
• Fewer air particles?> Lower pressure > less force
Force on air Reaction on wallHigh pressure
![Page 29: Introduction to Aerodynamics Let’s keep it simple, shall we? Why is it important and how does it affect my car? Greenpower schools education event Castle.](https://reader035.fdocuments.in/reader035/viewer/2022081519/56649cfd5503460f949cdef6/html5/thumbnails/29.jpg)
29
So where do the forces come from?A simple explanation…
• So what is pressure?> The force created when air particles bounce off things
• More air particles?> Higher pressure…bigger force
• Fewer air particles?> Lower pressure…less force
Force on air Reaction on wallLow pressure
![Page 30: Introduction to Aerodynamics Let’s keep it simple, shall we? Why is it important and how does it affect my car? Greenpower schools education event Castle.](https://reader035.fdocuments.in/reader035/viewer/2022081519/56649cfd5503460f949cdef6/html5/thumbnails/30.jpg)
30
So where do the forces come from?A simple explanation…
• But how does a moving car change the air pressure?
Car
Air
![Page 31: Introduction to Aerodynamics Let’s keep it simple, shall we? Why is it important and how does it affect my car? Greenpower schools education event Castle.](https://reader035.fdocuments.in/reader035/viewer/2022081519/56649cfd5503460f949cdef6/html5/thumbnails/31.jpg)
31
So where do the forces come from?A simple explanation…
• But how does a moving car change the air pressure?
Air
Car
![Page 32: Introduction to Aerodynamics Let’s keep it simple, shall we? Why is it important and how does it affect my car? Greenpower schools education event Castle.](https://reader035.fdocuments.in/reader035/viewer/2022081519/56649cfd5503460f949cdef6/html5/thumbnails/32.jpg)
32
So where do the forces come from?A simple explanation…
• But how does a moving car change the air pressure?
Car
Air
![Page 33: Introduction to Aerodynamics Let’s keep it simple, shall we? Why is it important and how does it affect my car? Greenpower schools education event Castle.](https://reader035.fdocuments.in/reader035/viewer/2022081519/56649cfd5503460f949cdef6/html5/thumbnails/33.jpg)
33
So where do the forces come from?A simple explanation…
• But how does a moving car change the air pressure?
Car
Air
High pressureLow pressure
![Page 34: Introduction to Aerodynamics Let’s keep it simple, shall we? Why is it important and how does it affect my car? Greenpower schools education event Castle.](https://reader035.fdocuments.in/reader035/viewer/2022081519/56649cfd5503460f949cdef6/html5/thumbnails/34.jpg)
34
So where do the forces come from?A complicated explanation…
• For the older amongst you, we’ll take a look at the Bernoulli principle and turbulence
![Page 35: Introduction to Aerodynamics Let’s keep it simple, shall we? Why is it important and how does it affect my car? Greenpower schools education event Castle.](https://reader035.fdocuments.in/reader035/viewer/2022081519/56649cfd5503460f949cdef6/html5/thumbnails/35.jpg)
35
So where do the forces come from?A complicated explanation…
• For the older amongst you, we’ll take a look at the Bernoulli principle and turbulence
• Bernoulli principle> The theory explaining why aeroplanes fly
![Page 36: Introduction to Aerodynamics Let’s keep it simple, shall we? Why is it important and how does it affect my car? Greenpower schools education event Castle.](https://reader035.fdocuments.in/reader035/viewer/2022081519/56649cfd5503460f949cdef6/html5/thumbnails/36.jpg)
36
So where do the forces come from?A complicated explanation…
• For the older amongst you, we’ll take a look at the Bernoulli principle and turbulence
• Bernoulli principle> The theory explaining why aeroplanes fly
• Turbulence> A method through which energy and pressure is lost
http://www.efluids.com/efluids/gallery/gallery_images/wake.jpg
http://www.hiflykites.co.za/kite-online-shop/x-zylo-flying-principles-3.gif
![Page 37: Introduction to Aerodynamics Let’s keep it simple, shall we? Why is it important and how does it affect my car? Greenpower schools education event Castle.](https://reader035.fdocuments.in/reader035/viewer/2022081519/56649cfd5503460f949cdef6/html5/thumbnails/37.jpg)
37
So where do the forces come from?Bernoulli principle…
• If air moves faster, its pressure will decrease.
![Page 38: Introduction to Aerodynamics Let’s keep it simple, shall we? Why is it important and how does it affect my car? Greenpower schools education event Castle.](https://reader035.fdocuments.in/reader035/viewer/2022081519/56649cfd5503460f949cdef6/html5/thumbnails/38.jpg)
38
So where do the forces come from?Bernoulli principle…
• If air moves faster, its pressure will decrease.
![Page 39: Introduction to Aerodynamics Let’s keep it simple, shall we? Why is it important and how does it affect my car? Greenpower schools education event Castle.](https://reader035.fdocuments.in/reader035/viewer/2022081519/56649cfd5503460f949cdef6/html5/thumbnails/39.jpg)
39
So where do the forces come from?Bernoulli principle…
• If air moves faster, its pressure will decrease.
![Page 40: Introduction to Aerodynamics Let’s keep it simple, shall we? Why is it important and how does it affect my car? Greenpower schools education event Castle.](https://reader035.fdocuments.in/reader035/viewer/2022081519/56649cfd5503460f949cdef6/html5/thumbnails/40.jpg)
40
So where do the forces come from?Bernoulli principle…
• If air moves faster, its pressure will decrease.
![Page 41: Introduction to Aerodynamics Let’s keep it simple, shall we? Why is it important and how does it affect my car? Greenpower schools education event Castle.](https://reader035.fdocuments.in/reader035/viewer/2022081519/56649cfd5503460f949cdef6/html5/thumbnails/41.jpg)
41
So where do the forces come from?Bernoulli principle…
• If air moves faster, its pressure will decrease.
![Page 42: Introduction to Aerodynamics Let’s keep it simple, shall we? Why is it important and how does it affect my car? Greenpower schools education event Castle.](https://reader035.fdocuments.in/reader035/viewer/2022081519/56649cfd5503460f949cdef6/html5/thumbnails/42.jpg)
42
So where do the forces come from?Bernoulli principle…
• If air moves faster, its pressure will decrease.
![Page 43: Introduction to Aerodynamics Let’s keep it simple, shall we? Why is it important and how does it affect my car? Greenpower schools education event Castle.](https://reader035.fdocuments.in/reader035/viewer/2022081519/56649cfd5503460f949cdef6/html5/thumbnails/43.jpg)
43
So where do the forces come from?Bernoulli principle…
• If air moves faster, its pressure will decrease.
![Page 44: Introduction to Aerodynamics Let’s keep it simple, shall we? Why is it important and how does it affect my car? Greenpower schools education event Castle.](https://reader035.fdocuments.in/reader035/viewer/2022081519/56649cfd5503460f949cdef6/html5/thumbnails/44.jpg)
44
So where do the forces come from?Bernoulli principle…
• If air moves faster, its pressure will decrease.
• The distance between air particles is bigger on the top surface than the bottom!
![Page 45: Introduction to Aerodynamics Let’s keep it simple, shall we? Why is it important and how does it affect my car? Greenpower schools education event Castle.](https://reader035.fdocuments.in/reader035/viewer/2022081519/56649cfd5503460f949cdef6/html5/thumbnails/45.jpg)
45
So where do the forces come from?Bernoulli principle…
High pressure
Low pressure
• If air moves faster, its pressure will decrease.
• If air moves slower, its pressure will increase.
![Page 46: Introduction to Aerodynamics Let’s keep it simple, shall we? Why is it important and how does it affect my car? Greenpower schools education event Castle.](https://reader035.fdocuments.in/reader035/viewer/2022081519/56649cfd5503460f949cdef6/html5/thumbnails/46.jpg)
46
So where do the forces come from?Bernoulli principle…
• Look at the image to the right…
![Page 47: Introduction to Aerodynamics Let’s keep it simple, shall we? Why is it important and how does it affect my car? Greenpower schools education event Castle.](https://reader035.fdocuments.in/reader035/viewer/2022081519/56649cfd5503460f949cdef6/html5/thumbnails/47.jpg)
47
So where do the forces come from?Bernoulli principle…
• Look at the image to the right…
• Imagine you can see the air as you move with the car
• Air in front of the car is slowed down
• It’s pressure therefore increases
> This pushes the car back and tries to slow you down!
![Page 48: Introduction to Aerodynamics Let’s keep it simple, shall we? Why is it important and how does it affect my car? Greenpower schools education event Castle.](https://reader035.fdocuments.in/reader035/viewer/2022081519/56649cfd5503460f949cdef6/html5/thumbnails/48.jpg)
48
So where do the forces come from?Bernoulli principle…
• Look at the image to the right…
• But what about behind the car?
![Page 49: Introduction to Aerodynamics Let’s keep it simple, shall we? Why is it important and how does it affect my car? Greenpower schools education event Castle.](https://reader035.fdocuments.in/reader035/viewer/2022081519/56649cfd5503460f949cdef6/html5/thumbnails/49.jpg)
49
So where do the forces come from?Bernoulli principle…
• Look at the image to the right…
• “The air behind the car is moving slowly too, doesn’t that push the car forward?!”
• Ah, now that’s where turbulence comes in!
![Page 50: Introduction to Aerodynamics Let’s keep it simple, shall we? Why is it important and how does it affect my car? Greenpower schools education event Castle.](https://reader035.fdocuments.in/reader035/viewer/2022081519/56649cfd5503460f949cdef6/html5/thumbnails/50.jpg)
50
So where do the forces come from?Turbulence…
• Blunt bodies like cars will generally have a turbulent area in the air behind them, but what is turbulence?
http://www.efluids.com/efluids/gallery/gallery_images/wake.jpg
![Page 51: Introduction to Aerodynamics Let’s keep it simple, shall we? Why is it important and how does it affect my car? Greenpower schools education event Castle.](https://reader035.fdocuments.in/reader035/viewer/2022081519/56649cfd5503460f949cdef6/html5/thumbnails/51.jpg)
51
So where do the forces come from?Turbulence…
• In certain situations, air flow will become very turbulent
• This means it is chaotic and difficult to predict
• The physics involved means energy and pressure is lost
http://www.cvphysiology.com/Hemodynamics/H007%20turbulent%20vs%20laminar%20flow.gif
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So where do the forces come from?Turbulence…
• An example of turbulence…aeroplanes!
• Ideal flight:
• As explained before, the air moves faster over than under the wing, creating an upwards force called lift.
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• An example of turbulence…aeroplanes!
• Flying through turbulence:
• When flying through turbulence, the chaotic movement of the air prevents the difference in pressure from happening> This means the pressure above and below the wing is almost the same, so there’s no lift!
• The bouncing you feel when you fly in turbulence is due to the aeroplane losing lift, and then getting it back again!
So where do the forces come from?Turbulence…
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So where do the forces come from?Turbulence…
• Turbulence can be created a number of ways, the most important to us are:
> Moving over fast changes in shape> eg if the back of your car has a sharp corner
> Air of different speeds meeting each other and mixing> eg fast air from the top of your car meeting slow air from the bottom
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So where do the forces come from?Turbulence…
Fast air
Slow air
Turbulent mixture
• Turbulence can be created a number of ways, the most important to us are:
> Moving over fast changes in shape> eg if the back of your car has a sharp corner
> Air of different speeds meeting each other and mixing> eg fast air from the top of your car meeting slow air from the bottom
![Page 56: Introduction to Aerodynamics Let’s keep it simple, shall we? Why is it important and how does it affect my car? Greenpower schools education event Castle.](https://reader035.fdocuments.in/reader035/viewer/2022081519/56649cfd5503460f949cdef6/html5/thumbnails/56.jpg)
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So where do the forces come from?A complicated explanation…
• The Bernoulli principle and turbulence combine to create a drag force on your car slowing it down!
• Now I’ll show you some easy tricks to minimise these effects
High pressure Low pressure
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HOW CAN I MAKE MY CAR FASTER?!
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How can I make my car faster?!
• It’s simple, minimise the pressure change at the front and back of your car!> But how?
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How can I make my car faster?!
• It’s simple, minimise the pressure change at the front and back of your car!> But how?
• Imagine we start with a very bad car
Track
High pressure Low pressureHigh pressure Low pressure
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How can I make my car faster?!
• Begin by rounding the front end to prevent pressure building up at the front
Track
High pressure Low pressureHigh pressure Low pressure
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How can I make my car faster?!
• But air flowing under the car also slows us down because it’s close to the track> So we lower the tip of the nose to make more air go over the top
Track
High pressure
Low pressure High pressureLow pressure
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How can I make my car faster?!
• Taper the rear of the car to increase the pressure there, and reduce that pesky turbulence!
Track
High pressureLow pressure
Low pressureHigh pressure
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How can I make my car faster?!
• Finally, make your car as small as possible, so there’s less of it for the air to push on!
High pressureLow pressure
High pressure Low pressure
Track
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How can I make my car faster?!
• The difference can be very big…
Before…………High pressure Low pressure
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How can I make my car faster?!
• The difference can be very big…
Before………… …………After
High pressureLow pressure
High pressure Low pressure
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How can I make my car faster?!
• Differences made to our car this year…
Before………… …………After
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ANY QUESTIONS?
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YOUR TURN!