The noise in the engine intake system of a tractor is overlarge, which seriously affects physical and mental health of drivers. So, it is necessary to make a noise reduction design. Firstly, the intake noise characteristics are analyzed based on experimental tests. Secondly, based on the theory of straight-through perforation tube, the perforation tube is treated as a resonant silencing element. A multi-cavity resonance-type silencing structure is proposed for broadband noise reduction. Meanwhile, the Virtual.Lab software is used to simulate the acoustic performance of the muffler. Finally, the muffler is assembled into the tractor to verify the effectiveness of the proposed structure. It is shown that the numerical simulation results agree well with the experimental results. The designed muffler can effectively reduce the intake system noise and the amount of noise elimination can achieve 15 dB(A), which is superior to the requirement of the national standard.%某型号拖拉机的发动机进气系统噪声过大,严重影响驾驶员身心健康,需对其进行降噪设计.首先,基于试验测试,分析进气噪声特征.其次,基于直通穿孔管消声理论,将直通穿孔管结构看做一种共振消声单元,提出并设计一种针对宽频带噪声的多腔共振型消声器结构.同时,采用声学有限元软件Virtual.Lab对该消声器声学性能进行仿真研究.最后,将该消声器加装在实车上进行试验验证.结果表明,数值模拟结果与试验结果能较好吻合,所设计的消声器能明显降低发动机进气噪声,消声量达到15 dB(A),优于国标要求.
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