多孔扩散型消声器外壳对其性能影响的研究

Effect of the outer casing of a porous diffusion type silencer on the noise reduction of silencer

多孔扩散型消声器由于其体积小、消声性能高而广泛应用到排气噪声的降低上，其外壳对消 声器的消声性能具有重要作用．本文对此类消声器外壳的孔型、孔径和孔距以及外壳同消声材料的 配合方面进行了细致的实验研究，特别对外壳与消声材料的配合与其排放噪声以及外部流场之间的 关系进行了探讨，得到了一些有用的结论，对消声器性能的提高具有一定指导意义．

The porous diffusion type silencer is widely used to reduce the air flow noise because of its small volume and high noise attenuating ability. The out case of the silencer plays a very important role in reducing noise. The effect of the hole's shape, diameter and the distance between neighboring holes as well as the matchup between the case and the sound absorbing material tube are investigated experimentally. The relation between the out-flow noise and the gas velocity distribution is carefully studied for two different kinds of matchup between the case and the sound absorbing material tube. Some useful results are gotten, which may be valuable to the design of the silencer.