Aerodynamic Wind Tunnel in Passenger Car Application

Sammanfattning: The thesis aims to provide an evaluation on the Volvo 1/5th scaled wind tunnel regarding its potentials and capabilities in aerodynamic study. The flow quality in the test section was evaluated. The experiments were performed included measurements of airspeed stability, tunnel-wall boundary layer profile and horizontal buoyancy. A numerical model was developed to predict the boundary layer thickness on the test floor. Repeatability tests were also conducted to establish the appropriate operating regime.A correlation study between the 1/5th scaled wind tunnel (MWT) and full scale wind tunnel (PVT) was performed using steady force and unsteady pressure measurements. The Volvo Aero 2020 concept car was selected to be the test model.The Reynolds effect and the tunnel-wall boundary layer interference were identified in the steady force measurements. Unsteady near-wake phenomena such as wake pumping and wake flapping were discussed in the unsteady base pressure measurements.