基于CAE的柴油机进气系统声学优化

摘要

The noise of intake system is a major sound source for diesel engines,this problem is effectively solved in this paper by the way of designing intake muffler.First,based on spectrum analysis of inlet noise signal of diesel engine,the noise frequencies that need to be improved were indentified.Then combining the transfer matrix method with the finite element analysis,the muffler with resonance structure was designed;its vibration characteristics was obtained and optimized based on the modal analysis technique.Finally,the experimental results show that the inlet noise is suitably reduced;and the surface radiation noise is lower than the inlet noise.Therefore the muffler designed in this paper could meet the requirements for reducing noise of the intake system.%针对某柴油机,通过对进气噪声的频谱分析,确定了需要改善的噪声频段;结合传递矩阵法和有限元数值分析,设计了共振型消声结构;基于模态特性,研究与优化了消声器的振动声学响应。试验测试表明,消声器能有效的降低了进气口噪声,同时其表面噪声较进气口低,基本不影响进气系统的噪声水平。结合有限元数值方法,综合考虑了消声器的声学、流体和机械振动特性并进行了优化,最终消声器能满足设计要求。