Evaluation of Various Turbulence Models in Predicting Airflow and Turbulence around a Generic Vehicle Model

Abstract

For vehicle external aerodynamic computation, the selection of the turbulence model is very important. In current research, ten RANS turbulence models were introduced to compute the time-averaged flow field around the Ahmed model with 25° backlight angle. In order to evaluate the feasibility of the turbulence model, the results were compared with the related published experimental data. The results showed that the two equations RANS turbulence models were more favorable to compute the vehicle external flow field, but parts of the two equations turbulence model just could predict the aerodynamic drag coefficient or lift coefficient effectively. However, the results further revealed that the realizable k-ε could obtain the more accurate drag coefficient and lift coefficient simultaneously, and simulate the complex separation flow in the wake.