Experimental characterization of noise radiation from a ducted propeller of an unmanned aerial vehicle
A.M.N. Malgoezar (TU Delft - Aircraft Noise and Climate Effects)
Ana Alves Vieira (TU Delft - Aircraft Noise and Climate Effects)
M. Snellen (TU Delft - Aircraft Noise and Climate Effects)
D. G. Simons (TU Delft - Aircraft Noise and Climate Effects)
Leo L.M. Veldhuis (TU Delft - Flight Performance and Propulsion)
More Info
expand_more
Other than for strictly personal use, it is not permitted to download, forward or distribute the text or part of it, without the consent of the author(s) and/or copyright holder(s), unless the work is under an open content license such as Creative Commons.
Abstract
Ducted propellers are an interesting design choice for unmanned aerial vehicle (UAV) concepts due to a potential increase of the propeller efficiency. In such designs, it is commonly assumed that introducing the duct also results in an overall noise reduction. The objective of this work is to experimentally analyze and quantify noise of a ducted propeller suitable to be installed on a medium size UAV (wingspan 5–10 m). A microphone array is used for recording the noise levels at each microphone position and used collectively to localize noise sources with beamforming. Different types of noise sources are considered (an omni-directional source and a propeller). In addition, the effect of the presence of an incoming airflow is assessed. With no incoming airflow, it is found that the duct significantly modifies the noise radiation both in the frequency and the spatial domain. With an incoming airflow, the effect of the duct on the frequency content of the signal is almost eliminated. The fact that for this case the harmonics become lower results in a reduction of the received noise levels. Also the directivity changes. These insights are of importance in efforts towards modeling the effects of ducts for complex noise sources such as propellers.
help_outline