Based on the large eddy simulation (LES) and Ffowcs Williams and Hawkings (FW-H) equation, a multi-field coupling method is presented for aeroacoustic prediction of a muffler with high-speed and high-temperature exhaust gasflow. A three-dimensional finite-volume model of the muffler is established by using the LES and FW-H acoustic analogy (FW-H-AA) methods. Experimental validations of the simulated results suggest a good accuracy of the combined LES and FW-H-AA approach. Some factors influencing on noise attenuation, such as the gasflow velocity, temperature and the structural parameters of the muffler are analyzed. The results show that the aerodynamic noise and turbulent kinetic energy (TKE) are mainly attributed to the structural mutations in the muffler. The outlet sound pressure level (SPL) increases with the inlet gasflow velocity and decreases with temperature. According to the factor analysis results, the target muffler is modified by adding a fillet transition to the end of inserted tube and redesigning the structures where the TKE concentrated for improving the aerodynamic performance. In terms of the outlet SPL, the inner TKE and the backpressure of the muffler, the modified muffler is significantly improved by the maximum reductions of 3-5dB in SPL, 10–20% in TKE and 0.5–2.5 kPa in backpressure. The presented method might be extended to other kinds of muffler for aeroacoustic calculation and improvement design.

基于大涡模拟（LES）和Ffowcs Williams and Hawkings（FW-H）方程，提出了一种多场耦合方法，用于高速高温排气流消声器的气动声学预测。通过使用LES和FW-H声学类比（FW-H-AA）方法，建立了消声器的三维有限体积模型。模拟结果的实验​​验证表明，LES和FW-H-AA组合方法具有良好的准确性。分析了影响消声的一些因素，如气流速度，温度和消声器的结构参数。结果表明，空气动力噪声和湍动能（TKE）主要归因于消声器中的结构突变。出口声压级（SPL）随入口气流速度增加而随温度降低。根据因素分析结果，通过在插入管的末端添加圆角过渡并重新设计TKE集中的结构来改进空气动力学性能，从而对目标消声器进行了修改。在消声器的出口SPL，内部TKE和背压方面，改进后的消声器通过最大降低SPL 3-5dB，降低TKE 10-20％和背压0.5-2.5 kPa而得到显着改善。所提出的方法可以扩展到其他类型的消声器，以进行空气声计算和改进设计。通过在插入管的末端添加圆角过渡，并重新设计TKE集中的结构以改善空气动力学性能，可以对目标消声器进行修改。在出口SPL，内部TKE和消声器的背压方面，改进的消声器通过最大降低SPL 3-5dB，TKE降低10–20％和背压0.5–2.5 kPa而得到了显着改善。所提出的方法可以扩展到其他类型的消声器，以进行空气声计算和改进设计。通过在插入管的末端添加圆角过渡，并重新设计TKE集中的结构以改善空气动力学性能，可以对目标消声器进行修改。在出口SPL，内部TKE和消声器的背压方面，改进的消声器通过最大降低SPL 3-5dB，TKE降低10–20％和背压0.5–2.5 kPa而得到了显着改善。所提出的方法可以扩展到其他类型的消声器，以进行空气声计算和改进设计。