Predictions of eVTOL Broadband Noise from High-Fidelity CFD Loads

This study examines the acoustics of a wing operating in the wake of a propeller. The propeller wing system is simulated at 24 knots cruise and 8° wing angle of attack. The propeller is simulated using an actuator line model, while the wing is simulated using two different turbulence models: a DDES turbulence model and a higher fidelity LES model. Chordwise compact loads, on-wing pressure surfaces, and pressure surfaces at distances of 2.34% and 10% thickness around the wing surface are used as inputs to PSU-WOPWOP to predict noise at an observer below the wing. Using on-wing surface pressures, the LES broadband noise predictions are 13.5 dB higher than DDES. Chordwise compact loads result in lower noise predictions than on-wing surface pressures, by 11.3 dB for LES and 2.3 dB for DDES. Using off-body pressure surfaces, DDES results remain similar to noise predictions from on-wing pressure surfaces, but with LES the broadband noise predictions are about 2.5 dB lower.