Experimental and Numerical Investigations of Flow Field of Automotive Rear View Mirror

Abstract:

Pressure and velocity fields of flow over an outside rear view mirror are investigated by wind tunnel test and numerical simulations,and their results are compared.The agreement of average static pressure and average velocity,standard deviation and power spectral density of fluctuating velocity between the results from wind tunnel test and the results from numerical simulations indicates that test results and numerical results validate each other,and the numerical simulation approach is feasible and can reflect the flow field characteristics of mirror.The features of the flow field downstream the mirror,as reflected by the average static pressure distribution of test section floor,show that the position where the energy dissipation is the strongest is located at one diameter distance downstream of the mirror,and the recirculation zone can affect the flow field three diameters downstream of the mirror.High intensity fluctuating velocity can be found at the wake of mirror and their energy are foucs on low and middle frequency.The strength of fluctuating velocity at the shear layer region is larger than other regions.At the shear layer region,the σ(u′)/u进 value can reach 0.3 at certain point.

Key words:automotive rear view mirror; flow field; wind tunnel test; large eddy simulation