Analysis of Velocity Characteristics of Automobile Interior and Exterior Aerodynamic Noise

Abstract

After a short introduction about aerodynamic noise generation mechanisms, frequency and velocity characteristics of interior and exterior aerodynamic noise for a production automobile under different wind speeds are investigated through 1:1 aeroacoustic wind tunnel tests. The results show that: Both for the interior and exterior aerodynamic noise, the frequency characteristics keep almost the same as wind speed goes up. The linear OASPL for the interior aerodynamic noise increases at about 4.5th power of wind speed, for the pseudo noise on the vehicle body surface at 4.1th power, for the exterior noise out-of-flow also at 4.1th power. However, the A-weighted OASPL for the interior aerodynamic noise increases at about 5.2th power of wind speed, for the exterior noise out-of-flow at 6.0th power.