eVTOL Rotor Noise Study Using Combined Comprehensive Modeling with Acoustic Analysis

Interest in eVTOL air vehicles has increased significantly in recent years. Most development efforts for eVTOL aircraft have addressed conventional performance objectives. However, the acoustic noise remains a critical aspect that must be dealt with due to its significant impact on operations. This paper summarizes a study of eVTOL rotor acoustic noise variation using a CFD augmented comprehensive rotorcraft modeling and simulation tool combined with acoustic analysis that was validated against measured eVTOL drone rotor noise data. The paper presents a thorough parametric investigation of the variation of the rotor/propeller acoustic signature with emphasis on the broadband noise that often dominates in eVTOL rotor/propeller operation. The parametric study has investigated the effect of a range of rotor parameters, including number of rotor blades, rotor solidity, tip Mach number, blade planform (e.g., chord distribution), etc. The study has revealed important acoustic characteristics of eVTOL rotors. Several findings from the study are fundamentally unique to eVTOL rotors, which provide physical insight into supporting low noise eVTOL rotor/propeller design and development.