Aerodynamic Noise Simulation of a Car Side Mirror at Hight Speed

Abstract

Airflow around the car side mirrors is one of the sensitivity zones in which the airflow is separated and detached from the mirror flat side. The turbulence created by this flow detachment can affect the airflow to the main body of the car which lies behind the mirror. The turbulent structures of airflow exert directly on the lateral panels that causes the reduction of the car performance due to the increased drag, the source of noise and vibration, and so on. Consequently, the analysis of airflow structure allows for better understanding of the aerodynamic phenomena that is the origin of noise source and provides design information to improve and optimize the side mirrors. In this paper, the focus lies on the aerodynamic noise simulation by analyzing the turbulent flow structure and predict the external acoustic field using k-ε and LES turbulent modeling approaches. The numerical results are compared to the experimental results with only 6.7% error in static pressure on the mirror surfaces. The simulation results showed that the spectra of sound pressure level with LES model is close to experimental data than that with k-ε model.