双层串联微穿孔板吸声体吸声特性研究

Study on the Acoustic Characteristics of Double-layer Micro-perforated Panel Absorbers

单层微穿孔板的吸声频带较窄,采用双层串联微穿孔板结构可进一步拓宽其吸声频带,但由于双层串联微穿孔板结构的吸声曲线中两个波峰之间有很大的下降趋势致使整体吸声系数有所降低,故采用传递函数法建立双层串联微穿孔板吸声体理论模型,分析两层穿孔板的穿孔参数和板后空腔改变时结构整体吸声系数的变化,并通过与COMSOL中所建模型的计算结果相对比进行验证,比选确定合适的结构参数,使其在拓宽吸声频带的同时保持其在吸声频带内的吸声系数均较大,得到较优的吸声效果。

Because of the narrow absorption frequency band of micro-perforated panels, it is necessary to broaden the band by using the double-layer micro-perforated panel absorbers. However, due to the great downward trend of the difference between the two peaks in the sound absorption curves of the two micro-perforated panels, the overall sound absorption coefficient of the absorber decreases greatly. In this paper, the theoretical model of the acoustic absorber with the double-layer micro-perforated plate is established using the transfer function method. The change of absorption coefficient due to the different perforation parameters and cavity depth are analyzed. The result of the analysis is verified by comparing it with the computation result of the model by means of COMSOL. Finally, the suitable parameters are selected to broaden the acoustic absorption frequency band and make sure that the absorber has larger absorption coefficients in the full acoustic absorption frequency band so that a better absorption effect of the absorber can be obtained.