A study on the aerodynamic noise of automotive rearview mirrors relative to different side window openings

Abstract This study focused on the aerodynamic noise characteristics of the classic Volkswagen Beetle in the A-pillar-rearview mirror of the front side window at different opening levels using the Ansys-Fluent CFD software. First, the changes in wind-induced vibration noise were analyzed under the conditions of a 1/8 window opening and vehicle speeds of 40 km/h, 80 km/h, and 120 km/h. Results show that as the vehicle speed increases, the wind-induced vibration noise level rises, but when the window opening is 1/8, the noise increase is relatively small, and the in-car ventilation demand can be effectively met. The study further focused on a vehicle speed of 80 km/h, comparing the cases of window openings of 1/8, 1/2, and fully open. It was found that the larger the window opening is, the higher the wind-induced vibration noise level is, and the more severe the in-car airflow turbulence is. In contrast, when the window opening is 1/8, which is also a good opening level for both in-car ventilation and comfort, the aerodynamic noise impact is minimal.