Experimental investigation on motor noise reduction of Unmanned Aerial Vehicles

Multi-rotor Unmanned Aerial Vehicles (UAVs) are developing rapidly recently in usage and popularity in civil applications. However, although the great benefits UAVs have brought, their noise pollution is one of the concerns with their proliferation. The two main noise sources of a UAV are the motors and propellers. And the propellers are often assumed to be the dominant noise source in the literature, hence noise reduction of propeller becomes research focus; however, recent studies suggest that the contribution from the motor may also be important. This paper explore a passive noise reduction approach based on micro-perforated panel (MPP) absorbers together with sound-proof materials. Experimental results show that the proposed noise reduction constructions can have a significant reduction to the motor's overall noise level. (C) 2020 Elsevier Ltd. All rights reserved.