Aerodynamics:Aerodynamics:

Is the study of Air Flow around a Is the study of Air Flow around a moving vehicle.moving vehicle.

Good Aerodynamics offer the least Good Aerodynamics offer the least resistance.resistance.

Aerodynamics address four main Aerodynamics address four main areas of concern. (Frontal Pressure, areas of concern. (Frontal Pressure, Lift/Down Force and Drag.) Lift/Down Force and Drag.)

DragDrag

Enemy of race cars.

Drag, is comprised primarily of two forces, Frontal Pressure and Lift / Down Force.

These forces if not taken care of by good aerodynamic features can ruin a cars performance.

Frontal Pressure and Rear Frontal Pressure and Rear VacuumVacuum

Frontal Pressure is caused by the air attempting to flow around the front of the car.

Rear Vacuum is caused by the "hole" left in the air as the car passes through it.

Lift/Down ForceLift/Down ForceDown force is the same as the lift experienced by airplane

wings, only it acts to press down, instead of lifting up.

Not to be forgotten, the underside of the car is also responsible for creating a good amount of down force.

Aerodynamics in ActionAerodynamics in Action

Audi A4 Aerodynamics Demonstration

http://www.dailymotion.com/video/xrsf0_pub-audi-a4-aerodynamics-windtunnel_auto

http://www.tiz1.com/audi-a4-cars-2-videos/?tubepress_id=lg7N-HiPTRk

Air Flow Through DesignAir Flow Through Design

Which is Better?Which is Better?

What are the Key Designs on What are the Key Designs on this Vehicle?this Vehicle?

Aerodynamic TipsAerodynamic Tips

Have a minimized frontal area / small grill, to minimize Have a minimized frontal area / small grill, to minimize frontal pressure. frontal pressure.

Have minimal ground clearance below the grill, to Have minimal ground clearance below the grill, to minimize air flow under the car. minimize air flow under the car.

Converge Bodywork Slowly. Bodywork which quickly Converge Bodywork Slowly. Bodywork which quickly converges, forces the air flow into turbulence, and converges, forces the air flow into turbulence, and generates a great deal of drag.generates a great deal of drag.

Have a sloped windshield to avoid pressure build up in Have a sloped windshield to avoid pressure build up in front. front.

Have a "Fastback" style rear window and deck, to Have a "Fastback" style rear window and deck, to permit the air flow to stay attached. (Ideally 10° to 30°)permit the air flow to stay attached. (Ideally 10° to 30°)

Have a converging "Tail" to keep the air flow attached. Have a converging "Tail" to keep the air flow attached. Have a slightly raked underside, to create low pressure Have a slightly raked underside, to create low pressure

under the car.under the car. Cover Open wheels.Cover Open wheels. Open wheels create a great deal of Open wheels create a great deal of

drag and air flow turbulence, similar to the diagram of drag and air flow turbulence, similar to the diagram of the mirror above.the mirror above.

Current Land Speed Current Land Speed RecordRecord

Thrust SSCThrust SSC 763MPH at 763MPH at Black Rock Desert in Nevada, Black Rock Desert in Nevada,

USA, on 15 October 1997USA, on 15 October 1997.. Driven by Driven by Andy GreenAndy Green