Slotted-Wall Test Section for Automotive Aerodynamic Tests at Yaw

A test programme of surface pressure measurements on three car shapes at yaw angles from 0 to 30° in a l/5th-scale slotted-wall test section is described. Comparisons are made with corresponding “reference” results. The low-blockage reference results were obtained in an aeronautical wind tunnel with a solid-wall test section, using the same models and under similar aerodynamic simulation conditions. The comparisons verify results of our previous work (at zero yaw) in slotted-wall test sections. Extremely good vehicle surface pressure distributions can be obtained from tests at high blockage in appropriately designed slotted-wall test sections, even at high yaw angles. The important implication of the present results is that based on surface pressures, the overall size of a facility to give minimal wall-interference can be considerably reduced from the size of a solid-wall facility which would give an automotive aero dynamic simulation of comparable accuracy.