Hybrid Rotor Noise Optimization

Abstract

This study examines noise reduction strategies for unmanned aerial vehicles (UAVs) in urban air mobility applications, with a particular focus on package delivery. By employing a combination of low-, mid- and high-fidelity aerodynamic and aeroacoustic analyses, this research investigates the impact of rotor design parameters, including blade spacing and rotational speed, on noise emissions. The results demonstrate that an increase in rotor spacing results in a reduction in noise emissions. By adjusting the blade chord and twist within an optimization loop, it was possible to decrease tonal noise, yielding a Sound Pressure Level (SPL) reduction of about 3.51 dB while improving propulsive efficiency by 39%. These findings highlight the importance of rotor geometry optimisation during the early design stages in order to meet both performance and noise requirements.

Authors 3

1. Laura Babetto Aachen Institute of Aerospace Systems

   RWTH Aachen University

   Affiliation as printed

   Institute of Aerospace Systems, RWTH Aachen University, 52062 Aachen, Germany

2. Eike Stumpf Aachen Institute of Aerospace Systems

   RWTH Aachen University

   Affiliation as printed

   Institute of Aerospace Systems, RWTH Aachen University, 52062 Aachen, Germany

3. Christian Breitsamter

   Technical University of Munich

   Affiliation as printed

   Chair of Aerodynamics and Fluid Mechanics, Department of Mechanical Engineering, Technical University of Munich, 85748 Garching, Germany