船用柴油机涡轮增压器的进气消声器性能分析

Analysis of Marine Diesel Engine Turbocharger Intake Silencer Performance

为更好地进行船用低速柴油机涡轮增压器进气噪声控制,以现有自行设计的径向进气消声器为研究对象,探讨了其性能预测方法,并进行了相应的试验验证.结果表明:消声器对压气机性能影响较大,压气机性能计算时应将其考虑在内;采用管道声模态法计算了消声器传递损失,主要降噪频段及降噪量结果与试验测量值一致,消声器可以有效抑制高频段的增压器进气噪声,离散单音噪声峰值明显降低.在增压器高转速时,消声器对中、低频段的多重单音噪声峰值抑制能力有限,在原有消声器结构中加入声衬,可以使消声器低频和高频声学性能得到进一步优化.

A compact radial flow intake silencer was selected as research object for the intake noise control of the marine low speed diesel engine turbocharger and its performance prediction method was subsequently discussed,and then the corresponding experimental verifications were carried out. The results show that the resistance characteristics of the silencer have great influence on the compressor performance,thus the silencer structure should be unified considered in the compressor performance calculation. The duct acoustic mode method was employed to predict the transmission loss of the silencer,and the main frequency range and value of noise reduction were consistent with experimental measurement. It is seen that the intake silencer can greatly suppress high frequency intake noise,and it is especially effective for the discrete tonal noise peaks. But the noise reduction for low and medium frequency discrete Buzz saw noise peaks is not obvious when the turbocharger shifts to high speed. Adding an acoustic liner to the original silencer structure can further optimize the acoustic performance of the silencer at low frequency range and high frequency range.