Experimental Characterization of Wind Noise Excitation and Transmission Using a Production Automobile

A detailed set of data characterizing both the excitation and transmission of aerodynamically-generated noise acting on an automobile has been collected, using a production vehicle placed in the jet of BBN’s semi-anechoic wind tunnel. The steady aerodynamics were characterized through spatially dense measurements of the static pressure acting on the driver window. An equally dense set of measurements of the frequency spectra of wall pressure fluctuations was also obtained. In addition, the vibration of the driver window, and other vehicle surfaces, as well as the sound pressure levels at several points within the vehicle interior, were measured. An empirical model, relating noise at a given microphone location to the measured vibration of a specified surface, was developed. Results of this phaseless transfer function model were shown to agree well with measured noise levels.