Abstract:

The effect of catalytic converter structure on exhaust muffler was firstly researched.Sound transmits and loss were simulated by the establishment of new catalytic converter model which was full of inserted ducts,and transmission loss of the muffler and muffler with catalytic converter were analyzed and compared.Coupling simulation model of a motorcycle engine's working process and muffler with catalyst was established by GT-Power software,insertion loss and pressure loss of the exhaust muffler were obtained at different engine speeds.It is found that the muffling ability in middle and low-frequency is good,and in middle and high-frequency is bad.According to the calculation results,improvements on muffler structure are conducted.The simulation results show that the performance of the muffler at each speed of the engine is improved,and the insertion loss increases 3~5dB, the simulation results and the test results of this model tally well, and this design preferably meets the exhaust muffler performance requirements.

Key words: muffler, transmission loss, insertion loss, pressure loss, structure improvement

摘要：

研究了催化器结构对消声器性能的影响,在催化器内加入细插入管建立新催化器模型来模拟催化器的内噪声传递及损失,分析并对比了安装与未安装催化器的消声器的噪声传递损失,运用GT-Power软件建立摩托车发动机工作过程与带催化器的消声器的耦合仿真模型,得到消声器在发动机各转速下的插入损失和压力损失。分析结果显示,消声器在中低频段消声效果较好,在中高频段消声效果较差。根据仿真和试验结果对消声器结构进行改进,改进后的消声器在发动机各转速下消声效果得到改善,插入损失增加3~5dB,仿真结果与试验结果吻合良好。

关键词: 消声器, 传递损失, 插入损失, 压力损失, 结构改进