The primary advantage of an Adaptive Wall wind tunnel is that the test section walls and ceiling are contoured to closely approximate the ‘open road' flowfield around the test vehicle. This reproduction of the open road flowfield then results in aerodynamic forces and moments on the test vehicle that are consistent with actual open road forces and moments. Aerodynamic data measured in the adaptive wall test section do not require blockage corrections for adjusting the data to open road results.
Extensive full scale experiments, published scale model studies, and Computational Fluid Dynamics (CFD) studies have verified the simulation capability of adaptive wall technology. For the CFD study described here, high-downforce, open-wheel race cars were studied. The numerical simulations with a race car in an Adaptive Wall Test Section (AWTS) wind tunnel are compared with simulations in ‘free air' condition and in a closed wall test section. Wind tunnel simulation fidelity is quantified by comparing aerodynamic drag, downforce, and pitching moment values obtained in the wind tunnels to those values obtained on the open road.
Practical advantages of the Adaptive Wall Test Section configuration are also discussed. These include reduced wind tunnel power requirements resulting in operational savings, full optical access around the vehicle that supports the use of advanced measurement methods such as PIV and PSP, and the ability to study realistic aero-elastic effects on wings and other vehicle components.