Correction of Wind Tunnel Data: a Numerical Analysis of the Different Contribution

Abstract

The experimental data corrections on automotive wind tunnel tests usually benefit of pre-test corrections methodology, which can break down working time. This methodology is based on the use of CFD simulations and yields a global correction term, sum of different contributions. It is interesting to analyze such contributions and their possible dependencies by the involved parameters, in order to have a better comprehension of the phenomenon.

In the present paper, the main purpose is to describe, with the support of a CFD analysis, the influence of the wind tunnel walls, supports and Reynolds number effects, to the global correction factor. A high performances car was taken as reference and RANS equations were used as fluid dynamic model. The CFD methodology and its validation, through a comparison with experimental data, are preliminarily presented. Afterward, the contributions to the correction term are shown and discussed. Finally, is evaluated their effect on different elements of the car. The car was split in body, wheels, underbody, radiators, rear wing and internal volumes.