Abstract: Aiming at the issue of front window and interior aerodynamic noise caused by rear-view mirror, the numerical simulation of exterior rear-view mirror region and prediction of interior noise in a commercial vehicle are studied by using computational fluid dynamics (CFD) method. The SST(Menter)k-ω model in RANS model is used for steady-state analysis, and the detached eddy simulation based on the SST(Menter)k-ω model is used for transient analysis. By analyzing the nephograms of steady static pressure and transient dynamic pressure, velocity and vorticity, the mechanism of turbulent pressure fluctuation of side window caused by A-pillar and rear-view mirror is revealed, meanwhile the transient flow field is solved to obtain the surface turbulent pressure fluctuation load on two side windows. Acoustic FEM method is adopted to calculate the propagation of aerodynamic noise with the turbulent pressure fluctuation on window surface as boundary condition. Based on the distribution law of sound pressure level nephogram of interior acoustic space at different frequencies, it is indicated that the interior aerodynamic noise is mainly concentrated in the middle and low frequency ranges and the maximum distribution region of sound pressure level, and the sound pressure level curve at driver's left ear exhibits the variation law of the sound pressure level in the frequency range of 20-2 500 Hz. Finally, a real vehicle coasting road test is conducted, verifying the conclusion that the aerodynamic noise is more apparent at the speed range of 80-110 km/h. The adoption of CFD technique combined with acoustic FEM can relatively accurately predict the sound pressure level of interior aerodynamic noise at the frequency range of 100-2 500 Hz, providing technical schemes of simulation and test for optimizing rear-view mirror and reducing cabin aerodynamic noise

Key words: DES, rear-view mirror region, aerodynamic noise, turbulent pressure fluctuation, acoustic analogy, acoustic FEM