蒯家琛,杨溶,左承基

（合肥工业大学 机械与汽车工程学院,安徽 合肥 230009）

摘要：针对某款天然气发动机排气噪声偏大的问题，本文对该天然气发动机的排气消声器进行改进设计与试验。首先对原消声器进行现场测试与分析，得到噪声频谱图；然后利用Virtual.Lab软件对原消声器进行建模与仿真分析；再根据原消声器噪声频谱和仿真优化结果，设计了新型消声器；最后通过现场进行了效果验证。结果表明：本文所设计的新型消声器在该发动机高噪声的63、125和250 Hz频段上具有高的插入损失，满足该款天然气发动机在这三个频段上的降噪要求，使该机整体噪声降低23.5 dB。

关键词：抗性消声器；声学分析；传递损失；有限元     

Abstract:For this problem that a natural gas engine produces high noise, the paper redesigned and tested an exhaust muffler for the natural gas engine. First, it tested and analyzed the original muffler on site obtaining its noise spectrum, built modeling and did simulation analysis by Virtual. Lab software, and then designed a new muffler. The onsite tests validated its silencing effect. The results showed that the redesigned muffler achieved a high insertion loss at the three engine noise frequencies of 63,125 and 250 Hz, satisfying the demand of noise reduction of engines and reducing engine noise at 23.5 dB.

Keywords: resistance muffler； acoustic analysis； transmission loss； finite element