复杂结构消声器消声特性的数值分析及结构优化

Numerical analysis of acoustic characteristic of muffler with complicated structure and structural optimization

由于复杂结构消声器的内部声场比较复杂,平面波理论无法准确预测其分布,为了计算复杂结构消声器的消声特性,并进一步提高消声器的声学性能,在基本假设的前提下,合理处理进出口及壁面的边界条件,建立消声器内部声场的三维有限元模型,计算消声器的传递损失(TL)。然后,分析了不同的结构参数(隔板位置、内插管位置、进口管位置)对消声器的传递损失的影响,并优化了消声器的结构参数,有效地提高了消声器的消声性能,使得压缩机整机噪声降低了3.2 dB,验证了该分析方法的可行性,为复杂结构消声器的设计提供了参考依据。

Since the complicated pressure-distribution couldn＇t be predicted by plane wave theory, in this paper finite element method （FEM） was suggested for the simulation of the inner field of muffler, by which the transmission loss （TL） could be calculated. Firstly, based on the basic assumptions, boundary conditions （BC） were processed appropriately and the finite el- ement model of the muffler was modeled, and then it＇s transmission loss was calculated. Next, the facts of the influences of the following structural parameters on the transmission loss of mufflers were studied, which include. （1） the positions of rigid baffle in the chamber, （2） the positions of extended tube, （3） the positions of inlet tube, and structural parameters were optimized. Finally, the acoustic performance of the muffler was improved efficiently, through which the whole compressor- noise reduced by 3.2dB. This method is feasible and it can be used as a reference for the design of mufflers.