Senior Design Summer 2008 Presentation


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For my Senior Design class, we designed and built a formula style car and competed with it against 40 other schools. This presentation was to explain to the faculty and other students what our design plans were for the vehicle and where our deisgn was at that point of the summer.

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Senior Design Summer 2008 Presentation

  1. 1. EGR 400: Senior Design I Final Report Presentation Summer 2008 2009 Frame Front Rev B.
  2. 2. Introduction <ul><li>Objective </li></ul><ul><ul><li>Design, build, and compete with a small, formula style, race car. </li></ul></ul><ul><li>Plan </li></ul><ul><ul><li>Divide into four teams: </li></ul></ul><ul><ul><ul><li>Frame and Suspension </li></ul></ul></ul><ul><ul><ul><li>Brakes and Controls </li></ul></ul></ul><ul><ul><ul><li>Engine and Drive Train </li></ul></ul></ul><ul><ul><ul><li>Body and Miscellaneous </li></ul></ul></ul><ul><ul><li>Work in sub-groups as well as collectively with the entire class. </li></ul></ul>
  3. 3. 2009 Frame <ul><li>Used 2008 frame model as foundation for our design </li></ul><ul><li>Many changes were implemented and there are more to come </li></ul>
  4. 4. Design Goals <ul><li>Improve driver safety </li></ul><ul><ul><li>Prevent driver’s arms from hitting sides of cockpit </li></ul></ul><ul><li>Eliminate “C-notch” </li></ul><ul><li>Follow 2009 rules </li></ul><ul><ul><li>Two templates for cockpit </li></ul></ul><ul><ul><li>Knee clearance for front roll hoop </li></ul></ul><ul><ul><li>Two inches of clearance over driver’s head between front and main roll hoops </li></ul></ul><ul><li>Decrease weight of frame </li></ul><ul><li>Decrease wheel base from 64” to 60” </li></ul><ul><li>Shorten front of car while leaving room for pedals </li></ul><ul><li>Fit every component needed </li></ul>
  5. 5. Benchmarks in the road we’ve traveled <ul><li>June 22: build prototype frame out of MDF </li></ul><ul><li>Week of June 23: learn how to manipulate 2008 frame model </li></ul><ul><li>Week of July 24: make 2 different revisions of the model to compare concepts </li></ul><ul><li>Week of July 28: receive final front and rear suspension points from suspension team </li></ul><ul><li>August 6: selection revision B as design </li></ul>
  6. 6. Prototype Goals <ul><li>Elbow clearance </li></ul><ul><li>Foot pedal positions </li></ul><ul><li>Height of roll hoops </li></ul><ul><li>Line of sight </li></ul><ul><li>Angle of drivers seat </li></ul><ul><li>Adjustable for changes </li></ul><ul><li>Steering wheel mounting </li></ul>
  7. 7. Prototype Success
  8. 8. Rev A vs. Rev B <ul><li>Revisions made to model to correct weight distribution problems </li></ul><ul><ul><ul><li>Revision A: </li></ul></ul></ul><ul><ul><ul><li>62.75” wheelbase </li></ul></ul></ul><ul><ul><ul><li>Rear tire back 2” </li></ul></ul></ul><ul><ul><ul><li>Revision B: </li></ul></ul></ul><ul><ul><ul><li>63.75” wheelbase </li></ul></ul></ul><ul><ul><ul><li>Rear tire back 1” </li></ul></ul></ul><ul><ul><ul><li>Driver forwards 1” </li></ul></ul></ul>
  9. 9. Driver safety 2008 Frame 2009 Frame
  10. 10. Side impact structure
  11. 11. C-notch
  12. 12. Templates Must fit in seating area Must fit in leg area
  13. 13. Templates
  14. 14. Suspension Points
  15. 15. Interaction with engine team <ul><li>Met with engine team </li></ul><ul><li>Engine compartment has approximately equal room to 2008 car, space won’t be an issue </li></ul><ul><li>Engine mounts will be added to the model after they are designed </li></ul>
  16. 16. FEA with CosmosWorks
  17. 17. Material Properties <ul><li>Material properties obtained from MatWeb. </li></ul><ul><li>Custom material created in SolidWorks. </li></ul><ul><li>Material Properties: </li></ul><ul><ul><li>S ut = 128 ksi </li></ul></ul><ul><ul><li>S y = 113 ksi </li></ul></ul>
  18. 18. Torsional Stiffness <ul><li>Methodology: </li></ul><ul><ul><li>Back and left front were restrained. </li></ul></ul><ul><ul><li>Torque of 2000 ft-lbs was applied at the right front. </li></ul></ul><ul><ul><li>Deflection of right front was measured in inches. </li></ul></ul><ul><ul><li>Torsional Stiffness was calculated as follows: </li></ul></ul>
  19. 19. Torsional Stiffness
  20. 20. Worst Case Stress <ul><li>Methodology: </li></ul><ul><ul><li>Back restrained and a weight hung from the front. </li></ul></ul><ul><ul><li>At 90 lbs max stress was 104.2 ksi </li></ul></ul><ul><ul><li>At 110 lbs max stress was 127.3 ksi </li></ul></ul>
  21. 21. Case 1 Suspension <ul><li>Methodology </li></ul><ul><ul><li>Force vectors for the three main scenarios were obtained from the suspension team. </li></ul></ul><ul><ul><li>Force vectors were applied to each of the 16 suspension points. </li></ul></ul><ul><ul><li>The rear was restrained. </li></ul></ul>
  22. 22. Case 1: Worst Case Stress <ul><li>Max stress occurred at the left rear lower A-arm suspension point </li></ul><ul><li>Max stress was 35.92 ksi </li></ul><ul><li>Factor of safety against yielding is 3.15 </li></ul><ul><li>Factor of safety against failure is 3.56 </li></ul>
  23. 23. Case 1: Displacement
  24. 24. Case 1: Bending Stress <ul><li>Max stress occurred at the right rear A-arm front suspension point </li></ul><ul><li>Max stress was 14.37 ksi </li></ul><ul><li>Factor of safety against yielding is 7.86 </li></ul><ul><li>Factor of safety against failure is 8.91 </li></ul>
  25. 25. FEA w/ ANSYS
  26. 26. Prepping the model
  27. 27. Creating the Mesh
  28. 28. Applying the forces
  29. 29. Results
  30. 30. What’s Next? <ul><li>Analysis needs to be completed for case 2 and case 3. </li></ul><ul><li>Results from ANSYS analysis need to be compared. </li></ul><ul><li>Anticipate similar results. </li></ul>
  31. 31. Conclusions from FEA <ul><li>We have a frame that will meet or exceed all the physical requirements. </li></ul>
  32. 32. Changes Planned <ul><li>Main roll hoop </li></ul><ul><ul><li>Radii of bends </li></ul></ul><ul><ul><li>Height </li></ul></ul><ul><li>Front roll hoop </li></ul><ul><ul><li>Radii of bends </li></ul></ul><ul><ul><li>Number of bends </li></ul></ul><ul><li>Main roll hoop bracing </li></ul><ul><li>Front suspension point member </li></ul><ul><li>Shoulder harness and back brace </li></ul><ul><li>Add gussets for shoulder harness and back brace </li></ul><ul><li>Engine mounts </li></ul>
  33. 33. Engine Sensors <ul><li>Sensors </li></ul><ul><ul><li>Throttle Position </li></ul></ul><ul><ul><li>Air Temperature </li></ul></ul><ul><ul><li>Water Temperature </li></ul></ul><ul><ul><li>Crank Position </li></ul></ul><ul><li>Each sensor delivers feedback to the ECU </li></ul><ul><li>Plan to add a Manifold Absolute Pressure sensor. </li></ul>
  34. 34. Engine Tuning <ul><li>Goals </li></ul><ul><ul><li>Began with acquiring a FSAE 4cly. Engine map from Performance Electronics. </li></ul></ul><ul><ul><li>Read the tuning manual for the ECU to understand the different parameters of the engine </li></ul></ul><ul><ul><li>Engine started </li></ul></ul><ul><ul><li>Tune engine </li></ul></ul>
  35. 35. Engine Tuning
  36. 36. Engine Tuning <ul><li>We tuned the engine </li></ul><ul><ul><li>Real World </li></ul></ul><ul><ul><li>Stand testing </li></ul></ul><ul><li>The fuel map is tuned to be the correct ratio </li></ul><ul><li>Spark map was left alone because that has more chance of damaging the engine </li></ul>
  37. 37. Engine Goals <ul><li>Acceleration and Deceleration compensations need more tuning </li></ul><ul><li>Re-tune the fuel and spark maps once the MAP sensor is installed </li></ul><ul><li>Also, need re-tune for our intake and exhaust designs </li></ul><ul><li>Swap engines with 2008 FSAE car </li></ul>
  38. 38. Drive Train: Goals <ul><li>Improve upon current design </li></ul><ul><ul><li>Lighter/smaller differential </li></ul></ul><ul><li>Account for torque steer and misaligned sprocket </li></ul><ul><li>Improve acceleration </li></ul><ul><ul><li>Gear ratio </li></ul></ul><ul><ul><li>Larger rear sprocket </li></ul></ul>
  39. 39. Drive Train: Sprocket <ul><li>Use basic concept from current car </li></ul><ul><li>11 tooth pinion </li></ul><ul><li>At least 48 tooth rear sprocket </li></ul><ul><ul><li>Testing must be done to determine effectiveness of more teeth </li></ul></ul><ul><li>Gear ratio: 4.364 </li></ul>
  40. 40. Drive Train: Differential <ul><li>Design choices: </li></ul><ul><ul><li>Honda ATV diff. </li></ul></ul><ul><ul><li>Audi diff. (2007 FSAE) </li></ul></ul><ul><ul><li>Miata diff. (2008 FSAE) </li></ul></ul><ul><ul><li>New diff. </li></ul></ul><ul><li>Considerations: </li></ul><ul><ul><li>Ease of adaptation </li></ul></ul><ul><ul><li>Weight </li></ul></ul><ul><ul><li>Simplicity </li></ul></ul>
  41. 41. Drive Train- Axles <ul><li>Sprocket misalignment </li></ul><ul><li>Solution/Alternatives </li></ul><ul><ul><li>Center the differential </li></ul></ul><ul><ul><ul><li>Multi-stage gear </li></ul></ul></ul><ul><ul><ul><li>Larger differential housing </li></ul></ul></ul><ul><ul><li>Use different diameter axles </li></ul></ul><ul><ul><li>Provide calculations to prove design choices </li></ul></ul>
  42. 42. Drive Train- Axles <ul><li>Factory Specifications: </li></ul><ul><ul><li>Peak horsepower- 123hp </li></ul></ul><ul><ul><li>Peak RPM- 13000rpm </li></ul></ul><ul><ul><li>Pinion torque- 49ftlbf </li></ul></ul><ul><li>Gears: </li></ul><ul><ul><li>N p = 11 teeth </li></ul></ul><ul><ul><li>N g = 48 teeth </li></ul></ul><ul><li>Assumed dimensions: </li></ul><ul><ul><li>Short shaft- 16in, 1in diameter </li></ul></ul><ul><ul><li>Long shaft- 24in, 1 in diameter </li></ul></ul>
  43. 43. Drive Train- Axles <ul><li>Calculations: </li></ul><ul><li>Gear RPM- 2979rpm </li></ul><ul><li>Gear torque- 216ftlbf </li></ul><ul><li>Angle of twist </li></ul><ul><ul><li>Φ short = 1.04deg </li></ul></ul><ul><ul><li>Φ long = 1.56deg </li></ul></ul><ul><ul><li>Difference= .519deg </li></ul></ul><ul><li>Calculate the new diameter of the longer shaft: </li></ul><ul><ul><li>D long = 1.10in </li></ul></ul><ul><li>With: </li></ul><ul><ul><li>D short = 1.0in </li></ul></ul><ul><li>Not large enough to have an impact </li></ul><ul><li>Would require 2 different sized bearings </li></ul>
  44. 44. Intake <ul><li>Philosophy </li></ul><ul><li>Components of Intake </li></ul><ul><li>Calculations </li></ul><ul><li>Preliminary Design </li></ul><ul><li>Future Plans </li></ul>
  45. 45. Philosophy <ul><li>Effectively designed intake will improve volumetric efficiency </li></ul><ul><ul><li>Torque </li></ul></ul><ul><ul><li>Horsepower </li></ul></ul><ul><ul><li>Fuel efficiency </li></ul></ul>
  46. 46. Components of Intake <ul><li>Air Filter </li></ul><ul><ul><li>Removes impurities </li></ul></ul><ul><li>Throttle Body </li></ul><ul><ul><li>Manage air flow </li></ul></ul><ul><li>Restrictor </li></ul><ul><ul><li>FSAE mandated </li></ul></ul><ul><li>Plenum </li></ul><ul><ul><li>Air reservoir </li></ul></ul><ul><li>Fuel Injectors </li></ul><ul><ul><li>Fuel regulation </li></ul></ul><ul><li>Runners </li></ul><ul><ul><li>Cylinder air delivery </li></ul></ul>
  47. 47. Restrictor <ul><li>20mm Venturi Restrictor </li></ul><ul><li>Placed after throttle body </li></ul><ul><li>Severely limits air flow </li></ul>
  48. 48. Restrictor D 35 mm L1 35 mm R1 48.125 mm α1 21 Degrees R2 72.5 mm Dt 20 mm L3 6.67 mm R3 100 mm α2 7 Degrees R4 100 mm L5 35 mm
  49. 49. Plenum <ul><li>Smooth out turbulence </li></ul><ul><li>Even flow distribution </li></ul><ul><li>4-6X engine displacement </li></ul><ul><ul><li>3000cc </li></ul></ul><ul><li>Shape not yet determined </li></ul>
  50. 50. Runners <ul><li>Employed resonance equations </li></ul><ul><ul><li>L total =18” </li></ul></ul><ul><li>Primary tuning peak=5000 RPM </li></ul><ul><ul><li>Helmholtz peak=7500 RPM </li></ul></ul><ul><ul><li>Helmholtz peak=11250 RPM </li></ul></ul>
  51. 51. Preliminary Design <ul><li>Overhead Entrance </li></ul><ul><ul><li>Straight delivery=Minimal flow loss </li></ul></ul><ul><ul><li>Easier construction </li></ul></ul><ul><li>Side Entrance </li></ul><ul><ul><li>More bends=More flow loss </li></ul></ul><ul><ul><li>More difficult construction </li></ul></ul>
  52. 52. Preliminary Design
  53. 53. Future Plans <ul><li>Verify runner length </li></ul><ul><ul><li>Ricardo </li></ul></ul><ul><ul><li>Ohata & Ishida </li></ul></ul><ul><li>Better CAD model </li></ul><ul><li>CFD’s </li></ul><ul><li>Fabrication </li></ul>
  54. 54. Exhaust Design Overview <ul><li>Components </li></ul><ul><li>Header Design Considerations </li></ul><ul><li>Selected design </li></ul><ul><li>Muffler design Considerations </li></ul><ul><li>Selected Muffler </li></ul>
  55. 55. Exhaust Components <ul><li>Header </li></ul><ul><li>Collector </li></ul><ul><li>Muffler </li></ul>
  56. 56. Header Design Concerns <ul><li>Type of Header </li></ul><ul><ul><li>4 to 2 to 1 </li></ul></ul><ul><ul><li>4 to 1 </li></ul></ul><ul><li>Primary Pipe Length </li></ul><ul><li>Pipe Inner Diameter </li></ul><ul><ul><li>Stepped Pipe </li></ul></ul>
  57. 57. Header Design <ul><li>Competition Requirements </li></ul><ul><li>Final Design </li></ul><ul><ul><li>Primary Pipe Length </li></ul></ul><ul><ul><li>Pipe Diameter </li></ul></ul><ul><ul><li>Collector </li></ul></ul>
  58. 58. Muffler Design Concerns <ul><li>Muffler Types </li></ul><ul><ul><li>Resonance </li></ul></ul><ul><ul><li>Absorptive </li></ul></ul><ul><ul><li>Back Pressure </li></ul></ul><ul><li>Materials </li></ul><ul><ul><li>Titanium </li></ul></ul><ul><ul><li>Stainless Steel </li></ul></ul><ul><ul><li>Carbon Fiber </li></ul></ul>
  59. 59. <ul><li>Supertrapp </li></ul><ul><ul><li>Universal fit </li></ul></ul><ul><ul><li>Adjustable </li></ul></ul><ul><ul><li>Stainless Steel </li></ul></ul>
  60. 60. Suspension <ul><li>Goals: </li></ul><ul><ul><li>Maximize Friction </li></ul></ul><ul><ul><ul><li>Establishes ability to steer, brake, and accelerate </li></ul></ul></ul><ul><ul><li>Provide steering stability and feedback </li></ul></ul><ul><ul><ul><li>Determines the handling of the vehicle </li></ul></ul></ul>
  61. 61. Suspension Geometry <ul><li>King Pin Inclination </li></ul><ul><ul><li>2.5° </li></ul></ul><ul><ul><ul><li>Helps with packaging </li></ul></ul></ul><ul><ul><ul><li>Provides steering feedback </li></ul></ul></ul><ul><ul><ul><li>Increases steering effort </li></ul></ul></ul><ul><li>Scrub Radius </li></ul><ul><ul><li>.75” </li></ul></ul><ul><ul><ul><li>Similar effects as KPI </li></ul></ul></ul>
  62. 62. Suspension Geometry <ul><li>Static Camber </li></ul><ul><ul><li>Front: -1°, Rear: -.5° </li></ul></ul><ul><ul><ul><li>Negative camber maximizes the size of the tire patch </li></ul></ul></ul><ul><li>Caster </li></ul><ul><ul><li>4° </li></ul></ul><ul><ul><ul><li>Provides beneficial camber gain during steering </li></ul></ul></ul><ul><ul><ul><li>Increases steering effort </li></ul></ul></ul>
  63. 63. Front View Geometry <ul><li>Solidworks/Excel </li></ul><ul><ul><li>Parameters set in Excel and imported into Solidworks </li></ul></ul><ul><ul><ul><li>Solidworks used to cycle suspension through range of motion </li></ul></ul></ul><ul><ul><li>Results graphed in Excel </li></ul></ul>
  64. 64. Camber Curves
  65. 65. Stress Analysis <ul><li>Excel sheet used to find wheel loads </li></ul><ul><li>MathCAD file used to find forces in each member </li></ul><ul><li>Excel sheet used to calculate safety factors in tension, compression, and buckling </li></ul>
  66. 66. Suspension Dynamics: Tire Behavior <ul><li>Slip angle </li></ul><ul><li>Cornering force curve </li></ul><ul><li>Pneumatic trail </li></ul><ul><li>Aligning torque </li></ul><ul><li>Steering torque </li></ul>
  67. 67. Suspension Dynamics: Ride & Roll Rates <ul><li>Lateral Load Transfer </li></ul><ul><li>Wheel center rate </li></ul><ul><li>Ride rate </li></ul><ul><li>Roll rate </li></ul>
  68. 68. <ul><li>Worst case scenario: </li></ul><ul><ul><li>Critical speed at tightest turn </li></ul></ul><ul><li>Weight & CG Assumptions </li></ul><ul><li>Iterative design process </li></ul><ul><li>Preliminary results </li></ul><ul><ul><li>Roll gradient & body roll angle </li></ul></ul><ul><ul><li>Wheel, spring & anti-roll bar rates </li></ul></ul><ul><ul><li>Slip angle, aligning torque & steering torque </li></ul></ul>Suspension Dynamics: Ride & Roll Rate Calculations
  69. 69. <ul><li>Pull rod vs. push rod </li></ul><ul><ul><li>Lower CG & reduce weight </li></ul></ul><ul><li>Rocker arm </li></ul><ul><ul><li>Installation ratio of 1: increased sensitivity </li></ul></ul><ul><li>Anti-roll bar </li></ul><ul><ul><li>Blades: increased adjustability </li></ul></ul><ul><li>Shocks </li></ul><ul><ul><li>1’’ jounce, 1’’ rebound </li></ul></ul>Suspension Linkage Design Overview
  70. 70. Suspension Linkage Design Overview II
  71. 71. Suspension Linkage Design Overview III
  72. 72. Upright Design <ul><li>Design Goals </li></ul><ul><ul><li>Material </li></ul></ul><ul><ul><ul><li>Weight / Strength / Cost </li></ul></ul></ul><ul><ul><li>Easy to manufacture </li></ul></ul><ul><ul><li>Similar manufacturing procedure </li></ul></ul><ul><ul><li>KPI, Brakes, A-Arms, Steering </li></ul></ul><ul><ul><li>Prototypes </li></ul></ul>
  73. 73. Front Uprights
  74. 74. Rear Uprights <ul><li>Design Goals </li></ul><ul><ul><li>Interchangeable </li></ul></ul><ul><ul><li>Lightweight </li></ul></ul><ul><ul><li>Design Considerations </li></ul></ul><ul><ul><ul><li>A-arms </li></ul></ul></ul><ul><ul><ul><li>Tie-Rod </li></ul></ul></ul><ul><ul><ul><li>Bearing </li></ul></ul></ul>
  75. 75. Steering <ul><li>Design Goals </li></ul><ul><ul><li>No > 180 º for any turn </li></ul></ul><ul><ul><li>60º - 80º steer = 9.5m turn </li></ul></ul><ul><ul><li>Ratio for manageable steer </li></ul></ul><ul><ul><li>Rack total travel ≤ stock </li></ul></ul>
  76. 76. Steering <ul><li>Basic Geometry </li></ul><ul><li>Steering Calculation </li></ul><ul><ul><li>Find point B WRT A </li></ul></ul><ul><ul><li>Calculate angle CAB </li></ul></ul><ul><ul><li>Subtract arm angle </li></ul></ul><ul><ul><li>Subtract angle to vertical </li></ul></ul><ul><ul><li>Steering angle </li></ul></ul><ul><ul><li>Calculate Steering ratio </li></ul></ul>
  77. 77. Steering <ul><li>Ackermann Steering </li></ul>
  78. 78. Brakes <ul><li>Design Goals </li></ul><ul><ul><li>Max pedal force < 100lbf </li></ul></ul><ul><ul><li>No lock < 60lbf pedal force </li></ul></ul><ul><ul><li>Lock front wheels first </li></ul></ul><ul><ul><li>Built-in Bias </li></ul></ul><ul><ul><li>Light, Compact, Inexpensive </li></ul></ul>
  79. 79. Brakes <ul><li>System Layout </li></ul>
  80. 80. Aerodynamics <ul><li>Benefits </li></ul><ul><ul><li>Stability & Control </li></ul></ul><ul><ul><li>Increase Downforce </li></ul></ul><ul><ul><ul><li>Better Traction </li></ul></ul></ul><ul><ul><li>Air Flow Control </li></ul></ul><ul><ul><li>Drag Reduction </li></ul></ul>
  81. 81. Aerodynamics <ul><li>Drag Components </li></ul><ul><ul><li>Basic External Shape </li></ul></ul><ul><ul><ul><li>Less than Perfect Shape </li></ul></ul></ul><ul><ul><ul><li>Interference </li></ul></ul></ul><ul><ul><li>Internal Flow Devices </li></ul></ul><ul><ul><li>External Flow Devices </li></ul></ul><ul><ul><ul><li>Wheels & Wheel Wells </li></ul></ul></ul>
  82. 82. Aerodynamics <ul><li>Internal Flow Devices </li></ul><ul><ul><li>Goal: Optimize Cooling Efficiency </li></ul></ul><ul><li>Types </li></ul><ul><ul><li>Ram Air Ducts </li></ul></ul><ul><ul><ul><li>Nose </li></ul></ul></ul><ul><ul><ul><li>Side </li></ul></ul></ul><ul><ul><li>Scoops (High-Mounted Units) </li></ul></ul><ul><ul><li>Flush Duct (NACA Submerged Inlet) </li></ul></ul>
  83. 83. Aerodynamics <ul><li>Side Ram Air Duct </li></ul><ul><ul><li>Benefit: Easy Input & Output Adjustments </li></ul></ul><ul><li>Scoop </li></ul><ul><ul><li>Benefit: Low Speed Operations </li></ul></ul><ul><ul><li>Coverts Air Velocity to Pressure </li></ul></ul>
  84. 84. Aerodynamics <ul><li>External Flow Devices </li></ul><ul><li>Surface Roughness </li></ul><ul><ul><li>Permissible Grain Diameter = 0.0021in </li></ul></ul><ul><ul><ul><li>Same as for Unpainted Sheet Metal </li></ul></ul></ul><ul><li>Vortex Generators </li></ul><ul><ul><li>Control & Delay Flow Separation </li></ul></ul>
  85. 85. Aerodynamics <ul><li>Rear Wings </li></ul><ul><ul><li>Rear Downforce & Increased Deceleration </li></ul></ul><ul><li>Rear Spoilers </li></ul><ul><ul><li>Separate Air Flow & Rear Downforce </li></ul></ul><ul><li>Slotted Front Wings </li></ul><ul><ul><li>Frontal Downforce & Very Little Drag </li></ul></ul><ul><li>Rear Wheel Curved Guide Vanes </li></ul><ul><ul><li>Decrease Drag & Increase Downforce on Tires </li></ul></ul>
  86. 86. Aerodynamics <ul><li>Ground Effects </li></ul><ul><ul><li>“Sucker Car” </li></ul></ul><ul><ul><ul><li>Increased Downforce from 1.3 to 1.7g’s </li></ul></ul></ul><ul><ul><ul><li>Low Speeds </li></ul></ul></ul><ul><ul><li>Nose Angle </li></ul></ul><ul><ul><ul><li>Horizontal to 10° Down </li></ul></ul></ul><ul><ul><ul><ul><li>Lift Coefficient from -0.95 to -2.3 </li></ul></ul></ul></ul>
  87. 87. Aerodynamics <ul><li>Venturi Upsweep </li></ul><ul><ul><li>Controls strength of two vortices </li></ul></ul><ul><ul><ul><li>Height of Side Skirts </li></ul></ul></ul><ul><ul><li>Drawback </li></ul></ul><ul><ul><ul><li>Open Wheeled Vehicles Diminish Effects </li></ul></ul></ul>
  88. 88. Aerodynamics <ul><li>Testing </li></ul><ul><ul><li>Wind Tunnel </li></ul></ul><ul><ul><ul><li>Employ Correction Factors </li></ul></ul></ul><ul><ul><li>CAD Program </li></ul></ul><ul><ul><ul><li>Know Programs Limitations </li></ul></ul></ul><ul><ul><li>Calculate Frontal Area </li></ul></ul><ul><ul><ul><li>Guess Overall Drag Coefficient </li></ul></ul></ul><ul><ul><li>Estimate Drag Components </li></ul></ul><ul><ul><ul><li>Guess Interference Effects </li></ul></ul></ul>
  89. 89. Aerodynamics <ul><li>Conclusion </li></ul><ul><ul><li>Explored Variety of Aerodynamic Designs </li></ul></ul><ul><ul><ul><li>Promising Low Speed Design Options </li></ul></ul></ul><ul><ul><ul><ul><li>Side Ram Air Duct </li></ul></ul></ul></ul><ul><ul><ul><ul><li>Slotted Front Wings </li></ul></ul></ul></ul><ul><ul><ul><ul><li>Venturi Upsweeps </li></ul></ul></ul></ul><ul><ul><ul><li>Will Effect Handling </li></ul></ul></ul><ul><ul><ul><ul><li>Ability to “Grip” the Road </li></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Skid Pad </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Autocross </li></ul></ul></ul></ul></ul>