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Introduction to Aerodynamics Let’s keep it simple, shall we?

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 Bromwich Manufacturing Facility 1 st May 2013 Edward Sorby. Contents. What is aerodynamics? So where do the forces come from?

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Introduction to Aerodynamics Let’s keep it simple, shall we?

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  1. Introduction to AerodynamicsLet’s keep it simple, shall we? Why is it important and how does it affect my car? Greenpower schools education event Castle Bromwich Manufacturing Facility 1st May 2013 Edward Sorby

  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

  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?!

  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

  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

  6. What is aerodynamics?

  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

  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

  9. Why is aerodynamics so important in the design of a Greenpower racer?

  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

  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

  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

  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

  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!

  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!

  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!

  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

  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, well designed • 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

  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!

  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

  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

  22. So where do the forces come from?

  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 Low pressure High pressure

  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 Low pressure High pressure

  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 Low pressure High pressure

  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

  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

  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 High pressure Force on air Reaction on wall

  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 Low pressure Force on air Reaction on wall

  30. So where do the forces come from?A simple explanation… • But how does a moving car change the air pressure? Car Air

  31. So where do the forces come from?A simple explanation… • But how does a moving car change the air pressure? Car Air

  32. So where do the forces come from?A simple explanation… • But how does a moving car change the air pressure? Car Air

  33. So where do the forces come from?A simple explanation… • But how does a moving car change the air pressure? Car High pressure Low pressure Air

  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

  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

  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.hiflykites.co.za/kite-online-shop/x-zylo-flying-principles-3.gif http://www.efluids.com/efluids/gallery/gallery_images/wake.jpg

  37. So where do the forces come from?Bernoulli principle… • If air moves faster, its pressure will decrease.

  38. So where do the forces come from?Bernoulli principle… • If air moves faster, its pressure will decrease.

  39. So where do the forces come from?Bernoulli principle… • If air moves faster, its pressure will decrease.

  40. So where do the forces come from?Bernoulli principle… • If air moves faster, its pressure will decrease.

  41. So where do the forces come from?Bernoulli principle… • If air moves faster, its pressure will decrease.

  42. So where do the forces come from?Bernoulli principle… • If air moves faster, its pressure will decrease.

  43. So where do the forces come from?Bernoulli principle… • If air moves faster, its pressure will decrease.

  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!

  45. So where do the forces come from?Bernoulli principle… • If air moves faster, its pressure will decrease. • If air moves slower, its pressure will increase. Low pressure High pressure

  46. So where do the forces come from?Bernoulli principle… • Look at the image to the right…

  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!

  48. So where do the forces come from?Bernoulli principle… • Look at the image to the right… • But what about behind the car?

  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!

  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

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