Bian Haoyu, Tan Qichen, Zhong Siyang, Zhang Xin
Department of Mechanical and Aerospace Engineering, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong Special Administrative Region.
J Acoust Soc Am. 2022 May;151(5):3387. doi: 10.1121/10.0011399.
The Gaussian beam tracing method has advantages in computing long-distance noise propagation in outdoor environments due to its high efficiency. Usually, repeated computations are required if the target sound wave is broadband or contains multiple frequencies because the method was developed in the frequency domain. This paper presents an efficient computation of broadband noise propagation using Gaussian beam tracing. The approach is based on the fact that the ray behaviors and source properties can be decoupled at high frequencies, where the wave equation is asymptotically solved. Consequently, only a single computation is needed to determine the frequency-independent ray properties, including ray-centered coordinates and beam dynamics. Then sound waves at different frequencies can be simultaneously introduced in a single computation. By separating the processes of determining the ray properties and incorporating the broadband noise source in the numerical implementation, the computational cost can be largely saved. In this work, several benchmark problems are studied, showing that the efficiency could be increased in comparison to the multiple individual computations. A computation acceleration up to 35-fold could be achieved when 200 frequency components are applied. The method is also applied to study the impact of broadband noise due to multiple drone propellers in urban environments. Applications to stochastic broadband problems are also discussed.
高斯波束追踪方法因其高效性在计算室外环境中的长距离噪声传播方面具有优势。通常，如果目标声波是宽带的或包含多个频率，则需要进行重复计算，因为该方法是在频域中开发的。本文提出了一种使用高斯波束追踪的宽带噪声传播高效计算方法。该方法基于这样一个事实，即在高频情况下，波动方程可以渐近求解，此时射线行为和源特性可以解耦。因此，只需要一次计算就可以确定与频率无关的射线特性，包括射线中心坐标和波束动力学。然后，可以在一次计算中同时引入不同频率的声波。通过分离确定射线特性的过程并在数值实现中纳入宽带噪声源，可以大大节省计算成本。在这项工作中，研究了几个基准问题，结果表明与多次单独计算相比效率可以提高。当应用200个频率分量时，可以实现高达35倍的计算加速。该方法还被应用于研究城市环境中多个无人机螺旋桨产生的宽带噪声的影响。文中还讨论了该方法在随机宽带问题中的应用。
