Caracterização Experimental da Emissão Sonora de uma Hélice Dutada de um Veículo Aéreo não Tripulado

Abstract

Ducted propellers represent a promising design choice for unmanned aerial vehicles (UAVs) due to the potential for increased aerodynamic efficiency and noise reduction. However, the acoustic characteristics of ducted propellers are still little explored in the literature, especially in scenarios with ducts designed for specific applications. This work aims to experimentally characterize the sound radiation of a ducted propeller of a UAV, considering different configurations and operating conditions. Tests were performed with a pressurefield microphone and a decibel meter to measure the noise generated in two conditions: propeller in a closed duct and propeller without duct, operating at 2000, 3000, 3500, 4000 and 5000 RPM and at measurement angles of 0º, 30º, 60º and 90º. The duct was designed in CAD, manufactured via 3D printing and subjected to finishing to ensure geometric accuracy. The results indicate that the presence of the duct significantly influences noise levels, both in frequency and directivity, depending on its configuration. This study contributes to the understanding of the acoustic mechanisms associated with ducted propellers, with potential application in projects that aim to mitigate the environmental impact of UAVs in inhabited areas.