考虑微穿孔管消声器结构参数的共振频率预估模型

Resonant frequency predicting model for a micro-perforated tube muffler considering its structural parameters

引入微穿孔板声阻抗理论模型,通过微穿孔管消声器传声损失测试验证基于该模型的传声损失数值计算方法的正确性。利用数值方法计算微穿孔管消声器传声损失获得共振频率。单因素法分析穿孔段长度、穿孔率、穿孔直径和空气腔厚度等结构参数变化对共振频率影响发现,穿孔段长度及空气腔厚度对共振频率影响显著。利用均匀设计结合回归分析法所得共振频率预估模型,能直接反映微穿孔管消声器共振频率与结构参数之关系,对微穿孔管消声器优化设计具有指导意义。

The resonant frequency of a micro-perforated tube muffler （MPTM） is closely related to its parameters, such as, perforation segment length, perforation rate, perforation diameter and air-cavity thickness etc. Here, a theoretical acoustic impedance model of a mirco-perrorated plate （MPP） was introduced firstly and a measurement for transmission loss （TL） of a micro-perforated tube muffler was conducted to validate the correctness of the TL numerical calculation method based on the model introduced above. Then the MFFM＇s resonant frequency was obtained from the TL results calculated with the numerical calculation method. The effects of the MPTM＇s structural parameters on its resonant frequency were analyzed with the single factor analysis method. The results showed that perforation segment length and air- cavity thickness have significant effects on a MPTM＇s resonant frequency. Moreover, a resonant frequency predicting model for a MPTM was derived with the uniform design method and the regression analysis, it could reflect directly the relationship between a MPTM＇s resonant frequency and its structural parameters. The predicting model provided a guide for the optimal design of MPTMs.