Theoretical and experimental investigation of the aerodynamic noise generated by air flows through car windows

Motor vehicle aerodynamic noise characteristics have been investigated. A vehicle driver may be particularly annoyed at open-windows conditions. Thus, a measurement campaign has been carried out in order to characterize the aerodynamic noise generated by air flows through vehicle windows. Noise levels have been measured at the driver ears by varying vehicle speed and driver-side window opened area. Measurements results have shown that main noise component frequencies values depends on the following physical parameters: vehicle speed, car internal volume, window opened surface. Such results agree with the Helmoltz theory which has been employed to model the vehicle internal noise. A simple equation to evaluate global internal noise has been proposed. Estimated noise level values are very close to the experimental ones.