Buffeting noise analysis and optimization of commercial vehicle side windows based on detached eddy simulation method

To solve the problem of buffeting noise in the rearview mirror (RVM) and side window area of a commercial vehicle, the SST (Menter) k  model in the Discrete Eddy Simulation (DES) method was used to conduct buffeting noise simulation research and optimization, and the motion law of the original vehicle's aerodynamic vortex was analyzed. It is found that the periodic motion process of vortex formation, falling off, moving backward, crashing the B-pillar, and pressure wave rebound at the rear edge of the RVM causes the pressure pulsation in cab, which generated buffeting noise. Then, a progressive method was used to analyze the noise reduction around the three influencing factors of the RVM shape, the tilt angle of mirror cover and the installation distance, from which the optimal noise reduction scheme is designed and verified in real vehicles. The simulation results show that the streamlined RVM with gradually decreasing curvature, reducing the tilt angle of the RVM cover, and increasing the installation distance of the RVM can effectively reduce buffeting noise. The combination of the above three schemes has the best noise reduction effect, the SPL is reduce by 12.79 dB compare with the original vehicle.