The flow behind a full size serial car without modifications has been successfully measured at 60 km/h and 120 km/h with four high-speed cameras at 1450 frames per second in a wind tunnel at Volkswagen. The seeding rack, which emitted the 300 µm Helium-filled soap bubbles for seeding the flow, consisted of 6 x 10 nozzles in a vertical line and a overall height of 3.5 meters. The field of view was 4 m² with 200 mm depth.



These measurements resulted in the calculation of three dimensional velocity and vorticity using time-resolved tomographic PIV and volumetric PTV “Shake-the-Box” techniques.