Abstract: The exhaust muffler of a minibus is designed on the basis of analyzing the exhaust spectrum of B 12 engine. An engine-muffler coupled model is built using GT - Power software. Computational simulation and experimental verification of acoustic and aerodynamic performance of the muffler are presented. The result shows that the insert loss of the muffler can reach 25dB，the tail noise is about 95dB, and the backpressure is in 34±2 kPa of the allowable range. Hence, the goal of design of the muffler is successfully reached. It is shown by mutual comparison between the simulation and test results that GT-Power software has a good performance for prediction of the acoustic and aerodynamic behavior of the muffler.

Key words: acoustics, noise, auto engine, muffler, GT-Power

摘要： 在分析B12发动机排气频谱的基础上进行某微型车排气消声器设计。利用GT - Power软件建立排气消声器和发动机的耦合仿真模型，对消声器声学性能和空气动力学性能进行仿真计算，并进行实验验证。改进设计后消声器的插入损失可达到25 dB，尾管噪声控制在95 dB左右，背压在设计要求范围（34 ± 2 kPa）内，顺利完成设计目标。对比模拟和实验结果显示了GT - Power软件具有良好的预测性能。

关键词: 声学, 噪声, 发动机, 消声器, GT - Power