三维有限长声屏障声压简化算法

A Simplified Method for Calculating Acoustic Pressure of 3D Finite Length Noise Barriers

为了深入研究三维有限长声屏障的声学特性,采用理论模型预测法,基于声波绕射理论,在二维声屏障声压计算的基础上,考虑声屏障侧面绕射声的影响,给出了三维有限长单侧声屏障、平行声屏障的声压简化算法。为了验证简化算法的正确性,在Virtual.lab软件中利用快速多极边界元方法 (Fast Multipole Boundary Element Method,FMBEM)仿真声屏障的声学性能。通过算例将2种方法进行对比,在20～2 000 Hz频率范围内,计算结果基本吻合,趋势一致,计算单侧声屏障的声压时,平均绝对误差为1.95 dB,平均相对误差为2.98%;计算平行声屏障的声压时,平均绝对误差为2.43 dB,平均相对误差为3.75%,证明了该方法的可行性。简化算法公式简单实用、不需积分、便于计算,在设计声屏障时可减少复杂度,可为三维有限长声屏障的设计提供一定的参考,具有一定的工程价值。

In order to study the acoustic performance of 3D finite length noise barriers, by using theoretical model prediction, a simplified method for calculating the acoustic pressure of 3D finite length one-side noise barrier and parallel noise barriers was presented based on the theory of noise diffraction and 2D acoustic calculation considering diffraction around a harrier. Then the acoustic performance of noise barrier was emulated with fast muhipole boundary element method by software Virtual. lab. The calculation results pre and post simplification were compared through examples. It shows that （1） the acoustic pressure and curve tendency agree well in the frequency range of 20 - 2 000 Hz ; （2） when calculating acoustic pressure of oneside noise calculating barrier, the average absolute error is 1.95 dB and the average relative error is 2. 98% ; （3） when acoustic pressure of parallel barriers, the average absolute error is 2. 43 dB and the average relative error is 3.75 %. It proved the feasibility of the simplified method. Compared with other complicated method, this simplified method does not need integral. It is easier and more useful, which has reference value for research and design of 3D finite length noise barriers.