Noise Distribution Of Single Cylinder Diesel Engine And Exhaust Noise Control

In this paper, aiming at the noise reduction of diesel ZH1130, noise source identification is studied. And acoustic simulation which is based on Computational Fluid Dynamics (CFD) was applied to optimize the design of exhaust muffler to lower the sound power level (PWL) of the engine by controlling exhaust noise.In the Hemi-anechoic chamber, main noise sources are identified through different methods such as plumbum shielding,sound intensity measurement technique etc, which points out that exhaust noise do an important contribution to the sound power level of the engine.The CFD model of the muffler and engine are founded using software GT-POWER. The simulation result tallies well with the test result, which proves the reliability of the acoustic simulation method. After optimizing the parameters of muffler by the method, five new mufflers are designed.Engine bench test with new mufflers are processed. In contrast with the original muffler, new mufflers improve the silencing performance and reduce power loss. The insertion loss of the two new mufflers reach 21.5 dB(A) and 20.5 dB(A) separately, making the sound power level of the engine fall to 110.9 dB(A) and 111.4 dB(A) separately, both achieve the anticipative object.