Numerical analysis on aerodynamic drag of generic rear view mirror

To study the influence of the profile of automotive rear view mirror profile on aerodynamic drag,a numerical simulation on aerodynamic drag of a generic rear view mirror is carried out using Computational Fluid Dynamics(CFD) method based on a simplified rear view mirror model.The computational grids consist of 4.2 million hexahedral meshes.The turbulent flow is calculated by FLUENT with k-e Realizable 2-equation model,velocity-inlet and outflow are specified for inlet and outlet respectively,and the boundary condition of no-slip wall is specified on the surface of the rear view mirror and wind tunnel walls.The aerodynamic drag of the rear view mirrors with six kinds of profile parameters is simulated under different magnitude.Compared with the base model,the front face thickness,the length to width ratio,the upwind angle and the tangential edge angle have remarkable effect on aerodynamic drag of rear view mirror;the aerodynamic drag decreases with the increase of front face thickness and upwind angle and increases with the increase of edge angle;the rear face depth and the bracket length have little effect on the aerodynamic drag.The simulation results on surface pressure factor distribution is consistant with the experimental results.So it shows that the numerical simulation method is feasible for the study of the aerodynamic drag of rear view mirror,can provide a new research method on the profile optimization of rear view mirror,and has some reference value to the engineering development of rear view mirror.