柴油机缸盖罩隔声性能与透射噪声

Sound Insulation Performance and Transmission Noise of Engine Covers of Diesel Engine

以某柴油机缸盖罩为例,研究了柴油机薄壁件的隔声性能与透射噪声.采用结构-声耦合分析法对柴油机缸盖罩的隔声量进行了计算,并通过隔声性能试验验证了计算结果.设计了提取缸盖罩内部声场声压级的四负载法试验,并将结果施加到结构-声耦合计算模型中,计算了缸盖罩在发动机1,000,r/min、2,000,r/min和3,400,r/min全负荷工况下的透射噪声.研究发现,缸盖罩透射声功率主要分布在低频及隔声性能较差的高频范围;透射噪声在柴油机薄壁件辐射噪声中所占比重较大,对薄壁件辐射噪声进行预测和声学优化时,不能忽略透射噪声.

The sound insulation performance and the transmission noise of thin-walled components of diesel engines were studied by taking the engine cover of a certain diesel engine for example. The sound transmission loss of engine covers of diesel engine was predicted with structural-acoustic coupling method. A sound insulation performance ex-periment was conducted and its result was compared with the simulation results and they matched very well. An ex-periment with four load method was designed to get the interiorsound pressure and the experimental result was used in structural-acoustic coupling simulation model. The transmission noise at 1 000r/min,2 000r/min and 3 400r/min full load condition was calculated. And the results show that transmission sound power distributes in the low frequency and the high frequency in which sound insulation performance is poor. The percentage of transmission sound energy in total radiation sound energy is high and we can’t ignore the transmission noise when we predict acoustic performance of thin-walled parts of the engine and optimize its acoustical performance.