On Rotor Noise Optimization for Urban Air Mobility

Olívia Raquel Leite Pinto

Key information

Authors:

Olívia Raquel Leite Pinto (Olívia Raquel Leite Pinto)

Supervisors:

Frederico José Prata Rente Reis Afonso (Frederico Afonso); Fernando José Parracho Lau (Fernando José Parracho Lau)

Published in

04/06/2022

Abstract

This master thesis project presents an optimization study of the noise produced by rotors in the con- text of Urban Air Mobility. The importance of this study is based on the expected growth of Urban Air Mobility in larger cities across the globe and on the consequent effort to decrease the noise emitted by this type of aircraft. Provided that rotors constitute a major part of the noise produced by this aviation segment and given the fact that the aircraft are intended to be fully electric, the design of these components is of paramount importance for noise minimization. For the simulation accomplished within the optimization process, an open-source aerodynamic and aeroacoustic code (FLOWUnsteady, or FLight, Optimization, and Wind Unsteady) was integrated within an optimization module created specifically for the current thesis. These tools were based on the Formulation 1A of Farassat (PSU-WOPWOP) and the Brooks, Pope and Marcolini airfoil noise model (FLOWNoise), being utilized for the prediction of the tonal and atonal noise, respectively. The simulation code is applied to predict rotor noise which is posteriorly reduced by the means of an optimization algorithm, leading to the proposed optimal rotor design, with a reduction of 16,21% of the Energy Averaged Overall Sound Pressure Level (EAOSPL) having been achieved.