Reprint of: Assessment of UAM and drone noise impact on the environment based on virtual flights

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.