Computational Aeroacoustics of Various Propeller Designs for eVTOL Applications

Abstract

An in-house CFD solver, GPU-Accelerated Rotorcraft Flow-Field (GARFIELD),

was coupled to an acoustic code for a computational aeroacoustic framework to an-

alyze low aspect ratio propellers in hover such as those found on typical eVTOL

aircraft. Various design parameters including twist, planform, number of blades,

RPM, sweep, and disk loading were varied to evaluate their effect on aerodynamic

performance as well as the overall average sound pressure level (OASPL) experienced

by an observer. A nearby boom geometry was added to investigate the impact of

the unsteady airloads on the aeroacoustic performance. Aerodynamic loads were

also calculated by a BEMT analysis for comparison to the results predicted by CFD

in GARFIELD. The main drivers to reduce the OASPL were found to be RPM and

blade count. It was found that the boom geometry and all other design parameters

for the propellers did not have a significant impact on the aeroacoustic performance.