Technique for the Measurement of Sound Intensity and Its Utilization in Spotting the Noise Sources within Automobiles

Abstract

Auto noise is the main contaminated source of urban noises. Accurate identification of auto main noise sources is the premise of controlling auto noise. Sound intensity measurement is an important means of controlling automobiles noises. The principle of sound intensity measurement was discussed in this paper. The device of sound intensity measurement and its operating characteristics was analyzed. By using a sound intensity measurement system to measure noises of a certain kind of vehicle, the surface radiation noises distribution in the engine was researched in the engine. Through Analysis of zing the noise sources according to the test data result, the research results shows that the exhaust system and intake system are the main noise sources. The position of main noise sources could be determined accurately by the sound intensity measurement method. The frequency characteristics of main noise sources could be analyzed conveniently, and the rule and relevant characteristics about the engine noise was obtained. This method can provide a reasonable basis to correspondingly set down the for noise control strategies. Auto noise pollution is one of the major noise sources in the world. The main noises of automobiles are engine noises. It is necessary to reduce engine noises in order to reduce car noise. To do this, the paper must first identify the position and, frequency of its main sound sources at first, and then take some necessary measures to address the main noise sources. With its compact and complicated structure, the internal combustion engine has intense vibrations and a complex working process. Therefore, it is difficult to determine the distribution of the noise source effectively using general acoustic measurement technology. The sound intensity measurement technique is particularly suitable for noise source identification in internal combustion engines. It can effectively measure the size and distribution of the main noise source frequencies. Compared with general acoustic measurement techniques, it does not require a special acoustic environment. It can be done in general internal combustion engine bench test rooms with high efficiency (Pang, 2006).