Numerical Characterization of Acoustic Scattering in an Urban Air Mobility Configuration

This paper applies a time-domain numerical framework to investigate airframe scattering of both tonal and broadband noise for a full-size urban air mobility concept vehicle. The framework uses a stochastic approach to obtain time-domain realizations of broadband trailing edge noise, which are then scattered along with tonal noise using a time-domain boundary element method. Farfield noise predictions are presented including acoustic scattering from a simplified fuselage-only airframe geometry for both hover and cruise flight conditions. Significant variations are observed in the scattering effects between the tonal and broadband components and between the flight conditions. These variations are attributed to differences between the directivities and spatial structures of the rotor tonal and broadband noise components, as well as differences between the rotor positions and orientations in hover and cruise. Frequency-dependent scattering trends are also observed for the broadband component.