Question

A sport car has an inverted airfoil (the circled one) to generate a force that keeps its rear wheels on the ground at all the times when traveling at high speeds by applying Bernoulli’s principle.
a. Draw a diagram to show the direction of air flow and the direction of the force caused by air pressure.
b. Compare the air speed above and below the airfoil.
c. Compare the pressure above and below the airfoil. (20 marks)

Answer 1

Answer:

Jim Hall's Chaparral sports-racing cars in the 1960 s pioneered use of airfoils mounted above the rear suspension to enhance stability and improve braking performance. The airfoil was effectively 6 ft wide (span) and had a 1 -ft chord. Its angle of attack was variable between 0 and minus 12 degrees. Assume lift and drag coefficient data are given by curves (for conventional section) in Fig. Consider a car speed of on a calm day. For an airfoil deflection of down, calculate (a) the maximum downward force and (b) the maximum increase in deceleration force produced by the airfoil.