Effect of inlet turbulence parameters on numerical simulation of Ahmed car body

The features of air flows around simplified car model, Ahmed car body, are representative of that around automotive vehicles which move close to the ground. The paper is about the effect of inlet turbulence parameters on numerical simulation of Ahmed car body using a generic commercial CFD code STAR CD, based on comparison with reference experiment data. The linear low Reynolds number k-ε turbulence model was applied, and 8 computational models with different sets of inlet turbulent parameters under three main situations were simulated. The results imply that though the change of inlet turbulence parameters do sway the prediction in a certain extent, the effect is relatively slight regarding to the order of magnitude they change. Additionally, the present study finds out that, when turbulence viscosity is decided according to μ_t,μ =1~10, the numerical result tally with experiment data better.