关键词: 声学, 发动机噪声, 声全息技术, 近场声压法, 表面振动法, 噪声源识别

Abstract:

Acoustic holography technique was applied to the experiment of noise source identification for a 3 cylinder gasoline engine. In the first place, 1 meter sound pressure level test was put into effect respectively on the engine bench, which helped to find the intake side of the engine radiated the biggest noise. Then, acoustic holography test was experimented in the intake side, and came to a conclusion that the main noise source of the intake side locales in the generator area by analyzing sound pressure nephogram and noise spectrum, and the band of the frenquency is between 1000Hz and 2500Hz. To locate where the main noise source is, a new experiment combined near-field sound pressure and surface vibration methods was done in the generator area which is detected by acoustic holography. The result shows that both the frenquency band of vibration peak and noise peak are between 1000-2500Hz that is the same as the frenquency band detected by acoustic holograph, which proves the main noise source of the intake side is on the generator. Combined acoustic holography technique and traditional noise source identification methods to do the experiment of engine noise source identification, not only increase the efficiency of traditional methods, but the precision of acoustic holography technique.