Wake Surveys of Different Car-Body Shapes with Coloured Isopressure Maps

A technique to map the wake behind passenger cars with different rear end configurations has been developed in the full-scale automotive wind tunnel “Pininfarina”.

It is based on the measurement of total pressure in the wake, using a probe which is driven by a large traversing gear.

Results are presented as coloured isopressure maps.

Tests have been carried out on a 1:2.5 scale car model with two different front ends and eight different rear ends. The attainable body configurations are likely to cover the majority of passenger car shapes.

Wake surveys have been conducted at several distances behind each car model in order to see the wake development. The paper shows and analyzes the results obtained for these sixteen car model configurations; it also emphasizes what kind of information can be obtained by this wake survey technique.