Comparison of Different Turbulence Models and Wall Treatment Methods for Vehicle Aerodynamics Investigations

Abstract

In this paper two different turbulence models and wall treatment methods were investigated with Computational Fluid Dynamics (CFD) method. The used geometry for the research was the Ahmed body. The Ahmed body is a widely used geometry in vehicle aerodynamics investigations. The geometry represents a simplified vehicle, which allows the researchers to make examinations with moderate resources. The simulations were made in Ansys Fluent. The environment of the simulation was built to optimize for maximum 8 GB RAM. The paper examines the difference between the k-ω SST and the k-ε turbulence models in the case of low and high Reynolds number wall treatment methods. This could be useful because the high Reynolds number wall treatment method needs less computational capacity based on that, its required y+ range is between 30 and 300. While in the case of the low Reynolds wall treatment method the required y+ range is below 10, which could increase the cell count. The results from the CFD simulation will be compared to each other and with measured data. The aim of the research is to get information about behaviour of the examined turbulence models in the case of low and high Reynolds number wall treatment methods.