Effect of Turbulence Model on Simulation of Vehicle Aerodynamic Characteristics based on XFlow

摘要

The stability, comfort and safety of vehicles depend largely on the aerodynamic characteristics of the vehicle in high speed. As the turbulence model plays a decisive factor in the numerical simulation of aerodynamic characteristics, a simulation analysis of Ahmed model with a slant angle of 25° is carried out by the XFlow software. Then the paper presents the changes of aerodynamic parameters relative to the experimental values with four turbulence models: Spalart-Allmaras model, WALE model, Dynamic Smagorinsky model and Smagorinsky model. It is found that the result of simulation with Smagorinsky model is in good agreement with experimental value, and the simulation of the wake vortex separation is consistent with the actual phenomenon. The Smagorinsky turbulence model has a good simulation precision.