A Transient SEA Model for Transmission of Non-Stationary Wind Noise

Automakers have reported that passenger perception of vehicle interior wind noise is strongly correlated to the non-Gaussian and non-stationary character of the exterior aero-acoustic wind loading. Researchers in other domains have shown that leptokurtic non-Gaussian loading (Kurtosis κ>3) can be synthesized by non-stationary modulation of otherwise Gaussian random loading. This paper introduces a transient statistical energy analysis (SEA) model for the aero-vibro acoustic transmission of non-stationary wind noise which uses the same approach - a modulation of otherwise Gaussian random fluctuating pressure loading, in each one third octave band. The authors have previously shown that the non-stationary character of random wind loading can be measured in a wind tunnel or on the road with a suitable surface pressure microphone array. This paper reviews the formulation of a Transient SEA model and the predicted modulation frequency response functions for transmission of non-stationary exterior wind noise. Non-stationary wind noise test data is then used to show the validity of the model, correlating the modulation statistics of exterior surface pressure, with the modulation statistics of interior wind noise response.