某国产SUV排气系统声学改进及振动性能稳健性优化

为提升某国产SUV排气系统声品质及振动性能，优化了消声器内部结构并验证了优化方案的内部流场分布较理想。基于排气系统声学优化结构，建立了以挂钩垂向动态反力极值及其标准差、吊耳的静态变形量和静反力标准差为优化目标的多目标稳健优化模型。实车测试怠速及三挡全油门（3WOT）加速尾管噪声的总体及阶次噪声较原方案均有较大程度降低。振动性能优化结果表明，挂钩垂向动态反力极值及其标准差、吊耳静反力标准差都有明显降低。

Numerical Simulation of Vortex-Induced Vibration for 2D Square Cylinder Based on Parallel Computation for Fluid Domain

Based on Fluent 6, numerical simulation code for solving aeroelastic problems is first presented by using loosely coupled method in this paper. The fluid domain can be solved by adopting serial or parallel computation method, and the structure domain is solved by adopting Newmark method, and finally the interface coupling between the fluid and structure domains is implemented through dynamic mesh technique. The calculation process and the special method to deal with the parallel computation in fluid domain are then introduced. Finally, numerical simulation of vortex-excited vibration of a 2D square cylinder at Reynolds number of 22000 is done. The computed results and the comparison with those in literatures could verify the validity of the present program.