Your SlideShare is downloading. ×
0
Motorsport Aerodynamics Jamie  Arner Brian Feldman 16
Importance of Aerodynamics 2 12
Aerodynamic Design Methodology <ul><li>CFD </li></ul><ul><ul><li>Develop parts and visualize flow over car and devices bef...
Motorsports <ul><li>Highly Developed </li></ul><ul><li>Highly Secretive </li></ul><ul><li>Heavily Regulated </li></ul><ul>...
Front Air Dam <ul><li>Limits the Amount of Air Passing Underneath the Car </li></ul><ul><li>Contributes to High Pressure I...
Front Splitter Captures Some of the High Pressure Created In  Front of the Air Dam, Causing Downforce 13
Side Skirts <ul><li>Side Skirts Prevent High Pressure Air Around the Car from </li></ul><ul><li>Disturbing the Low Pressur...
Canards (French for Duck) <ul><li>Captures a Small Amount  </li></ul><ul><li>of Downforce by Redirecting </li></ul><ul><li...
Canard Vortices <ul><li>Vortices Spin Inwards, Towards the Vehicle on Each Side </li></ul><ul><li>Canard Vortices Work In ...
Venturi Tunnels / Rear Diffusers 5
Ground Effects <ul><li>Ride Height </li></ul><ul><ul><li>Downforce Increases  </li></ul></ul><ul><ul><li>with Reduced Clea...
Underbody Pressure <ul><li>Suction Peak Occurs Near the Diffuser Entrance </li></ul><ul><li>Can be used to Control the Veh...
Rear Diffuser <ul><li>Expands Air Back Down </li></ul><ul><li>to Road Velocity </li></ul><ul><li>Slows the Flow and Raises...
Diffuser Vortices <ul><li>Two Vortices form at the Side Edges  </li></ul><ul><li>of the Diffuser </li></ul><ul><ul><li>Flo...
Venturi Tunnels <ul><li>Venturi effect </li></ul><ul><ul><li>constricts the flow  </li></ul></ul><ul><ul><ul><li>creates l...
Underbody Vortices <ul><li>Induced vortex speeds up  </li></ul><ul><li>flow over F-16 wing </li></ul><ul><ul><li>Vortex Li...
Vortex Generators <ul><li>Trips the Boundary Layer, Causing the Laminar Air Traveling </li></ul><ul><li>Over the Roof to B...
Effect of VG’s on Flow Separation With VG Without VG VG Separation Region Separation Region 3
Effect on Bluff Bodies With VG Without VG <ul><li>Higher Velocities Closer to Car,  </li></ul><ul><li>Resulting in a Small...
Wing Endplates <ul><li>A Wing with Endplates is Equivalent to  </li></ul><ul><li>a Longer Wing Without Endplates </li></ul...
Gurney Flaps Typically 1% to 4% of the Wing Chord Length 5
Effect of a Gurney Flap on Flow <ul><li>At High Angles of Attack,  </li></ul><ul><li>Flow Separates </li></ul><ul><li>Addi...
How a Gurney Flap Works <ul><li>Vortices Reattach Flow and Redirect it Slightly Upwards  </li></ul><ul><li>Relative to the...
Gurney Flap Size Vs. Lift 6
Current Research on Gurney Flaps <ul><li>Von Karman Vortex Street  </li></ul><ul><li>Forms Downstream of  </li></ul><ul><l...
Additional Aerodynamic Considerations 9 5
Questions ? 14
References <ul><li>Jang et al, “Numerical investigation of an airfoil with a Gurney flap” 1998 </li></ul><ul><li>Katz, Jos...
Upcoming SlideShare
Loading in...5
×

Motorsport Aerodynamics

6,595

Published on

origional URL
http://engineering.union.edu/~brunob/Fluids%20II%20papers/Motorsport%20Aerodynamics.ppt

Published in: Technology, Business
1 Comment
2 Likes
Statistics
Notes
No Downloads
Views
Total Views
6,595
On Slideshare
0
From Embeds
0
Number of Embeds
0
Actions
Shares
0
Downloads
309
Comments
1
Likes
2
Embeds 0
No embeds

No notes for slide

Transcript of "Motorsport Aerodynamics"

  1. 1. Motorsport Aerodynamics Jamie Arner Brian Feldman 16
  2. 2. Importance of Aerodynamics 2 12
  3. 3. Aerodynamic Design Methodology <ul><li>CFD </li></ul><ul><ul><li>Develop parts and visualize flow over car and devices before models are built </li></ul></ul><ul><li>Wind Tunnel </li></ul><ul><ul><li>Scale model testing of devices </li></ul></ul><ul><ul><li>Full size testing of vehicle (rolling road) </li></ul></ul><ul><li>Track </li></ul><ul><ul><li>Devices are assessed and approved for racing </li></ul></ul>
  4. 4. Motorsports <ul><li>Highly Developed </li></ul><ul><li>Highly Secretive </li></ul><ul><li>Heavily Regulated </li></ul><ul><li>Extremely Competitive </li></ul>5
  5. 5. Front Air Dam <ul><li>Limits the Amount of Air Passing Underneath the Car </li></ul><ul><li>Contributes to High Pressure In Front of the Car </li></ul><ul><li>Causes Low Pressure Underneath the Car </li></ul>10
  6. 6. Front Splitter Captures Some of the High Pressure Created In Front of the Air Dam, Causing Downforce 13
  7. 7. Side Skirts <ul><li>Side Skirts Prevent High Pressure Air Around the Car from </li></ul><ul><li>Disturbing the Low Pressure Underneath the Car </li></ul>11
  8. 8. Canards (French for Duck) <ul><li>Captures a Small Amount </li></ul><ul><li>of Downforce by Redirecting </li></ul><ul><li>Airflow Upward. </li></ul><ul><li>Main Purpose is the </li></ul><ul><li>Creation of Large Vortices </li></ul><ul><li>That Run the Length of </li></ul><ul><li>the Vehicle </li></ul>5
  9. 9. Canard Vortices <ul><li>Vortices Spin Inwards, Towards the Vehicle on Each Side </li></ul><ul><li>Canard Vortices Work In Conjunction With Side Skirts to Limit the High Pressure Air From Mixing With the Low Pressure Air Found Underneath the Car </li></ul>5
  10. 10. Venturi Tunnels / Rear Diffusers 5
  11. 11. Ground Effects <ul><li>Ride Height </li></ul><ul><ul><li>Downforce Increases </li></ul></ul><ul><ul><li>with Reduced Clearance h </li></ul></ul><ul><ul><li>Diffuser Stall </li></ul></ul><ul><ul><ul><li>Individual to Each Design </li></ul></ul></ul>2
  12. 12. Underbody Pressure <ul><li>Suction Peak Occurs Near the Diffuser Entrance </li></ul><ul><li>Can be used to Control the Vehicle Center of Pressure </li></ul>12
  13. 13. Rear Diffuser <ul><li>Expands Air Back Down </li></ul><ul><li>to Road Velocity </li></ul><ul><li>Slows the Flow and Raises </li></ul><ul><li>the Air Pressure </li></ul><ul><li>Acts as a Pump Drawing </li></ul><ul><li>More Air from the Undertray </li></ul><ul><li>Rear Wing Drives the </li></ul><ul><li>Diffuser Because of its Proximity to the Wing's Low Pressure Side </li></ul><ul><li>Reduce the Overall Pressure Drag on the Vehicle by Introducing High Pressure Air into the Low Pressure Wake Region </li></ul>13
  14. 14. Diffuser Vortices <ul><li>Two Vortices form at the Side Edges </li></ul><ul><li>of the Diffuser </li></ul><ul><ul><li>Flow Separates at the Sharp Leading Edge </li></ul></ul><ul><ul><li>Reattached by the Side Vortices </li></ul></ul><ul><ul><li>Separation Line is Dictated by the Leading Edge </li></ul></ul><ul><ul><ul><li>Reynolds Number Effect Insignificant </li></ul></ul></ul><ul><li>Reasons for Loss of Downforce at Low Ground Clearance </li></ul><ul><ul><li>Vortex Breakdown </li></ul></ul>2 9
  15. 15. Venturi Tunnels <ul><li>Venturi effect </li></ul><ul><ul><li>constricts the flow </li></ul></ul><ul><ul><ul><li>creates low pressure </li></ul></ul></ul><ul><ul><ul><li>high velocity flow </li></ul></ul></ul><ul><li>Less pitch sensitive than flat bottom </li></ul><ul><li>Highly regulated to limit cornering speeds </li></ul>
  16. 16. Underbody Vortices <ul><li>Induced vortex speeds up </li></ul><ul><li>flow over F-16 wing </li></ul><ul><ul><li>Vortex Lift </li></ul></ul><ul><li>Vortex Generators speed </li></ul><ul><li>up flow at the front </li></ul><ul><ul><li>Strong stable vortex creates </li></ul></ul><ul><ul><li>suction loads along its trail </li></ul></ul><ul><ul><li>Bernoulli says air </li></ul></ul><ul><ul><li>pressure decreases </li></ul></ul>Strakes 12
  17. 17. Vortex Generators <ul><li>Trips the Boundary Layer, Causing the Laminar Air Traveling </li></ul><ul><li>Over the Roof to Become Turbulent </li></ul><ul><li>Typically the size of the boundary layer, </li></ul><ul><li>15mm - 30mm at the rear end of a vehicle roof </li></ul>13
  18. 18. Effect of VG’s on Flow Separation With VG Without VG VG Separation Region Separation Region 3
  19. 19. Effect on Bluff Bodies With VG Without VG <ul><li>Higher Velocities Closer to Car, </li></ul><ul><li>Resulting in a Smaller Wake Behind Vehicle </li></ul><ul><li>VG’s Cause Drag, but Reduce Pressure Drag by </li></ul><ul><li>Delaying Flow Separation from Occurring </li></ul><ul><li>Reducing the Magnitude of the Separation Region </li></ul><ul><li>Increases the Static Pressure of Separation Region </li></ul>3
  20. 20. Wing Endplates <ul><li>A Wing with Endplates is Equivalent to </li></ul><ul><li>a Longer Wing Without Endplates </li></ul><ul><li>Effective Aspect Ratio </li></ul><ul><li>Aspect Ratio (AR) = Span/Chord </li></ul><ul><li>AR_effective = </li></ul><ul><li>AR*(1+1.9*(Endplate Depth/Span) </li></ul>12
  21. 21. Gurney Flaps Typically 1% to 4% of the Wing Chord Length 5
  22. 22. Effect of a Gurney Flap on Flow <ul><li>At High Angles of Attack, </li></ul><ul><li>Flow Separates </li></ul><ul><li>Addition of Gurney Flap </li></ul><ul><li>Reattaches Flow </li></ul><ul><li>Can Increase the Downforce </li></ul><ul><li>of the Wing up to 30% </li></ul><ul><li>Can Provide the Same </li></ul><ul><li>Amount of Downforce with </li></ul><ul><li>3 O less Angle of Attack </li></ul>15
  23. 23. How a Gurney Flap Works <ul><li>Vortices Reattach Flow and Redirect it Slightly Upwards </li></ul><ul><li>Relative to the Flow Over a “Clean” Wing, Implying An </li></ul><ul><li>Increase in Circulation as the cause of increased </li></ul><ul><li>Downforce </li></ul>5
  24. 24. Gurney Flap Size Vs. Lift 6
  25. 25. Current Research on Gurney Flaps <ul><li>Von Karman Vortex Street </li></ul><ul><li>Forms Downstream of </li></ul><ul><li>Gurney Flap </li></ul><ul><li>Fluid of Negative Vorticity </li></ul><ul><li>Becomes “Trapped” </li></ul><ul><li>Upstream of Gurney Flap </li></ul><ul><li>Trapped Fluid Escapes, </li></ul><ul><li>Interfering Either </li></ul><ul><li>Constructively or </li></ul><ul><li>Destructively with </li></ul><ul><li>Downstream Vortices </li></ul><ul><li>Increases Circulation and </li></ul><ul><li>Downforce </li></ul>6
  26. 26. Additional Aerodynamic Considerations 9 5
  27. 27. Questions ? 14
  28. 28. References <ul><li>Jang et al, “Numerical investigation of an airfoil with a Gurney flap” 1998 </li></ul><ul><li>Katz, Joseph. “Aerodynamics of Race Cars” 2006 </li></ul><ul><li>Koike et al, “Research on Aerodynamic Drag Reduction by Vortex Generators” 2004 </li></ul><ul><li>Nikolic, “Additional Aerodynamic Features of Wing-Gurney Flap Flows” 2006 </li></ul><ul><li>Sport Compact Car Magazine “Automotive Aerodynamic: Part 2” </li></ul><ul><li>Troolin et al, “Time Resolved PIV Analysis of Flow Over a NACA 0015 Airfoil with Gurney Flap” 2006 </li></ul><ul><li>Troolin et al, “Time Resolved PIV Analysis of a Gurney flap on a NACA 0015 Airfoil” 2005 </li></ul><ul><li>Troolin et al, “The Effect of Gurney Flap Height on Vortex Shedding Modes Behind Symmetric Airfoils” 2006 </li></ul><ul><li>Zhang, Xin et al. “Ground Effect Aerodynamics of Race Cars” 2006 </li></ul><ul><li>www.army.mil/armyimages/armyimage.php?photo=6806 </li></ul><ul><li>www.autocult.com.au/img/gallery/997gt3773.jpg </li></ul><ul><li>www.mulsannescorner.com </li></ul><ul><li>www.seriouswheels.com </li></ul><ul><li>www.topgear.com </li></ul><ul><li>www.insideracingtechnology.com/tech107bndrylayer.htm </li></ul><ul><li>http://zedomax.com/blog/2007/04/19/rolling-wind-tunnel-that-goes-at-180mph/ </li></ul>
  1. A particular slide catching your eye?

    Clipping is a handy way to collect important slides you want to go back to later.

×