中文摘要：

针对柴油机传统排气消声器中低频消声性能差,排气背压高的问题,提出了一种基于反相对冲的新型消声原理.对基于新型原理消声单元的消声特性进行了理论建模,建立了其消声性能与结构参数间的关系.为了验证上述原理的正确性,以CG25型单缸柴油机为样机,设计试制了3种不同参数的反相对冲消声器.对安装3种消声器、5种转速下柴油机排气噪声的总A声级、倍频程声压级及详细频谱进行了测试分析,并与不装消声器及样机原装传统排气消声器下的排气噪声进行了比较分析,初步验证了该消声原理的正确性.

英文摘要：

To solve the problems of poor noise reduction in low-frequency domain and high exhaust resistance of traditional exhaust muffler,a new concept of engine exhaust muffler is proposed based on out-ofphase noise elimination and split-stream rushing.A mathematical model of the muffler for the new concept was established,and the relationship between performance and structural parameters is obtained.Three new mufflers with different parameters were designed and manufactured to test the consideration in a single-cylinder diesel engine.The sound level pressure dB（A）,octave-band sound pressure level as well as detailed spectrum of exhaust noise of the tested diesel engine at five different speeds with three mufflers were measured and compared with that without muffler and with original muffler.The correctness of muffler principle is verified.