车用内插管式消声器声学性能的研究

Research of Acoustic Performance for Inner Insertion-type Automotive Muffler

针对内燃机排气系统噪声给人耳带来的不舒适问题,通过实验测试研究了排气系统上游端的声源特性,根据其低频阶次的特征选择了传递矩阵法和有限体积法预测消声器的传递损失,实验验证这两种方法对研究消除排气压力脉动噪声有效。通过进一步研究内插管式消声器的消声性能,发现适当地改变内插管的长度能够有效地消除通过频率和改善特定频段消声效果。

Considering the discomfort caused by noises of internal combustion engine exhaust system,characteristics of sound source in the upstream of exhaust is studied by an experiment,according to the characteristics of order in low frequency range,Transfer Matrix Method and Finite Volume Method are chosen to predict transmission loss of muffler,experimental results show that the two methods are effective for the study of exhaust pressure pulsation noise. With further research of intubation acoustical performance,it was found that specific spectrum can be eliminated and specific spectrum silencing effect can be improved by changing the length of the intubation appropriately.