Noise of a Realistic Installed Propeller for eVTOL Vehicles

Due to the rapid urbanisation of cities, major traffic congestions and high levels of pollution, eVTOL are becoming a more viable option for mobility within cities. A significant amount of research has been devoted to the noise generated by model aircraft and scale propellers, with many of these studies producing results that are directly comparable to those observed in full-scale aircraft operations. This is sometimes due to anechoic chamber restrictions or simulation cost. These investigations provide a strong foundation for understanding the acoustic behaviour of novel configurations. Building upon this background, the focus of this presentation is on the aeroacoustics of a realistic wing-installed propeller system. The study involves a detailed examination of directivity patterns and noise source identification, with particular emphasis on evaluating how the presence of the wing influences the radiated far-field noise of the tested configuration. The findings indicate that the installation effects are most noticeable in the low-frequency region of the noise spectra. More specifically, the root section of the propeller blade is affected first, as the aerodynamic and acoustic characteristics change when the blades pass over the installed pylon and interact with the wing structure. These insights are crucial for understanding the mechanisms of installation noise and for guiding future design strategies aimed at minimising the acoustic footprint of eVTOL aircraft operating in urban environments.