Abstract:

The exterior noise of a truck was analyzed and predicted with the nearfield acoustic holography(NAH) and the space transformation of sound field(STSF). A measurement system of the NAH was built, a software of the STSF was developed, and they were used to measure and analyze the exterior noise source of the truck. The farfield noise characteristics and the maximal noise outside the accelerating truck were analyzed and predicted. The predicted farfield noise was validated by experiments, and the reasons causing error in acceleration noise prediction were discussed. The results showed that based on the nearfield holographic face measurement data, the sound field of the farfield arbilrary reconstruction face can be predicted with the STSF, the main noise source to form the planar sound field in that face can be identified, and the exterior maximal vehicle acceleration noise can be approximately predicted.

Key words: vehicle engineering, tacoustic holography, space transformation of sound field, vehicle exterior noise, noise analysis