中文摘要：

以三角截面内管阻抗复合型消声器为研究对象，推导其消声量数学表达式，基于GT-POWER软件建立消声器传递损失和阻力损失计算仿真模型，分析消声器结构、材料参数与消声性能的关系，得到孔径、穿孔率、变径管倾角、吸声材料及容重对消声器传递损失及背压的影响规律，并通过实验验证仿真结果的正确性。研究结果可为具有三角截面消声器的设计和优化提供参考。

英文摘要：

An impedance composite muffler with a triangular cross- section inner tube is studied. Mathematical expressions for noise elimination of the muffler are derived. Based on the GT-POWER software, the models of transmission loss and resistance loss of the muffler are established. By analyzing the relationship of muffler structure, material parameters and the acoustic performance of the muffler, the influence of aperture, perforation rate, inclined angle of the reducing pipe,parameters of the sound-absorbing materials and bulk density on the transmission loss and back pressure is obtained. The simulation results are verified by experiment. This work has provided a reference for design and optimization of mufflers with the triangular section inner tubes.