Numerical prediction of aerodynamic noise radiated from a propeller of unmanned aerial vehicles

Abstract

The demand for the development of small unmanned aerial vehicles (UAVs) has been growing in a wide range of industrial and commercial applications. UAV based on the multi-rotor platform, commonly called as a drone, has received considerable attention, owing to a user-friendly control system, simple mechanical structure, and vertical take-off and landing (VTOL) ability. However, the noise problem is one of the major hindrances for the widespread use of a drone, since the sound pressure level associated with the drone could lead to severe problems in mental health, such as annoyance, psychological distress, and stress. The main objective of this work is to predict the aerodynamic noise from quadcopter UAV, and the sound pressure level of the quadcopter is compared with that of isolated rotor one to investigate rotor-to-rotor interaction effects in terms of noise characteristics. In this study, nonlinear vortex lattice method (NVLM) coupled with vortex particle method (VPM) and acoustic analogy based on Farassat-1A formula are adopted as aeroacoustic analysis model, and numerical predictions are validated against measurements. Noise predictions of quadcopter configurations with different separation distances in hover flight are conducted. Discussion in this work will help to achieve a better understanding of the noise characteristics of multi-rotor systems.