摘要
基于声波传播理论,建立并推导了声波在弯管处的Helmholtz方程.采用COMSOL Multophysics软件的压力声学模块,对不同弯曲半径的直角弯管进行频域分析,研究了不同弯曲半径弯管内声波传播特性规律.研究结果显示,弯曲半径对弯管内声波散射系数和传输损耗具有显著影响,弯曲半径较大的弯管曲率较小,弯管内声波散射效应较弱,传输损耗较小,声压级较高;弯曲半径较小的弯管曲率较大,弯管内声波散射效应较强,传输损耗较大,声压级较低.低频段内,声波波长大于弯管弯曲半径,散射系数与传输损耗较小;高频段内,声波波长接近或小于弯管弯曲半径,散射系数与传输损耗较大.
Abstract
Based on the theory of sound wave propagation,the Helmholtz equation of the sound wave at the pipe bending was established and derived.In order to study the sound wave propagation characteristics of pipe bending with different bending radius,the frequency domain analysis of the right-angle pipe bending with different bending radius was carried out based on the pressure acoustic module in COMSOL Multophysics software.The analysis results show that the bending radius has a significant effect on the acoustic scattering coefficient and transmission loss in the bending.In the bending with a larger bending radius,the acoustic scattering effect is weaker and the transmission loss is smaller.On the contrary,the transmission loss in the smaller bending radius is higher due to the large curvature.In low-frequency bending,the acoustic wavelength is larger than the bending radius of the pipe,and the scattering coefficient and transmission loss are small;in high-frequency bending,due to the acoustic wavelength close to or smaller than the bending radius of the pipe bending,the scattering coefficient and transmission loss are large.
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