Drones and urban air mobility vehicles, which are mostly intended for urban operations, have attracted intensive research interest. Their environmental noise impact should not be ignored and should be a certification consideration. Numerical simulations can provide means to efficiently assess the noise impact on the complex urban environments, thanks to the advances in both software and hardware. In this study, virtual flights of the noise sources to mimic the drones and urban air mobilities are conducted to investigate the environmental impact by using the Gaussian beam tracing method implemented in an in-house solver Environmental Acoustic Ray Tracing Code, in which the dominant acoustic processes in outdoor applications are modelled. The solver also allows for modelling of sources with generic directivity patterns, which is beneficial for investigating the drone and urban air mobility noise produced by multiple rotors. Two examples of studying noise impact on building and realistic urban environment are conducted. The effects of the surface acoustic impedance, source type and flight path are investigated. By using the efficient simulation solver, the noise impact can be quickly assessed through virtual flights, providing a promising approach to assist the low-noise flight planning and noise certification.

无人机和城市空中机动车辆主要用于城市运营，引起了广泛的研究兴趣。它们的环境噪声影响不应被忽视，应作为认证考虑因素。由于软件和硬件的进步，数值模拟可以提供有效评估噪声对复杂城市环境影响的方法。在这项研究中，通过使用在内部求解器环境声学射线追踪代码中实施的高斯波束追踪方法，进行模拟无人机和城市空中交通的噪声源的虚拟飞行，其中主要声学室外应用中的过程被建模。求解器还允许对具有通用方向性模式的源进行建模，这有利于调查多旋翼产生的无人机和城市空气流动噪声。进行了两个研究噪声对建筑和现实城市环境影响的例子。研究了表面声阻抗、声源类型和飞行路径的影响。通过使用高效的仿真求解器，可以通过虚拟飞行快速评估噪声影响，为辅助低噪声飞行计划和噪声认证提供了一种很有前景的方法。