TYRE/ROAD NOISE GENERATION

At the last three ARRB conferences, the author has described various phases of his research on the measurement, analysis and generation of tyre/road noise. The present paper is concerned with perhaps the final component of that ongoing program annd details some of the more recent findings. A range of tyre/road noise data has been collected using the passby technique for a variety of tyres and road surfaces typical of those in service through Australia. Of particular interest in this paper are the data obtained using a set of experimental tyres of simple, handcut, yet not too unrealistic tread pattern. Using frequency analysis techniques, the passby noise spectral content associated with tyre, road and other vehicle noise sources have been identified. From there, the air pumping tyre noise generation model, previously developed by the author on the basis of a laboratory study of tyre noise, was extended to allow calculation of the passby noise monitored under the experimental tyre situation. More specifically the model has been shown to provide a reasonably good description of the tyre noise fluctuations that occur as a function of time during passby and of the overall passby tyre noise peak level. Consequently the model was found to represent a significant advance in the current understanding of the air pumping tyre/road noise generation mechanism. Applications of the results of this work are also considered, and these include low noise design criteria (a). The number of the covering abstract of the conference is TRIS No. 368448. (TRRL)