A Comparison of On-Track and Wind Tunnel Surface Pressure Measurements on a Compact SUV

Aerodynamic evaluation of passenger vehicles has been almost exclusively performed in the controlled, low turbulence environment provided in wind tunnels. Such conditions are rarely encountered on the road where the local atmospheric wind conditions give rise to velocity fluctuations and changes in turbulence characteristics. A preliminary study has been undertaken in an attempt to identify differences in surface static pressures measured during wind tunnel and on-track tests. Significant differences in the data from wind tunnel and track tests have been identified and discussed, justifying the need for further in-depth examination of the differences between wind tunnel and on-road testing. The use of surface static pressure tappings mounted around the nose of the vehicle, for use as a macro probe, has been conducted. Encouraging results were produced prompting further development of this technique.