等截面消声管道传递损失计算的简化方法

Simplified calculation method of transmission loss for silencing ducts with uniform cross-section

该文提出了等截面消声管道传递损失计算的简化方法,方法利用消声管道截面形式的特点,将三维声学计算问题简化为二维问题,消声管道的传递损失可以表示为与轴向波数有关的表达式,轴向波数可以通过计算截面的特征值得到。对于规则截面结构,使用传递矩阵法计算特征值;复杂非规则截面的特征值使用二维有限元方法得到,进而可以计算消声管道的传递损失。仿真结果与文献中的数值方法及实验值在较宽的频率范围内吻合较好,说明了方法的正确性,此外,该方法可以考虑均匀流对消声管道声学性能的影响。方法的计算效率高,对消声管道的前期优化设计具有实际意义。

Simplified method is employed in the paper for calculating the transmission loss(TL)of silencing ducts.Three-dimensional acoustic computation is simplified as two-dimensional problem considering the structure characteristics.TL is then expressed as function of axis wavenumber which can be obtained by eigenvalue analysis of the silencing duct cross-section.For duct with regular cross-section,transfer matrix method is used to obtain the eigenvalues,while for complex structures eigenvalue analysis is executed by 2D finite element method.Then the TL may be calculated.The simulation results are compared with simulation and experimental data in the literatures and good agreements are observed.Uniform flow may also be considered in the method.The method is of high computation efficiency and has practical application potential.