Noise Level Prediction of a Small UAV Using Panel Contribution Analysis

Panel contribution analysis and vibro-acoustic reciprocity is reviewed and applied to noise radiation from a hovering UAV. Measurements were performed on six measurement surfaces forming an imaginary box encompassing the UAV. A P-U Probe was utilized to measure both sound pressure and particle velocity on the imaginary surfaces. Acoustic transfer functions between the source and a receiver point located 5.5 m away from the UAV were measured. The noise level was predicted from measurements close to the UAV assuming both correlated and uncorrelated sources at the receiver point. The sound pressure level calculated by the correlated model compared well with direct measurement. In addition, a 1/10 scale was built to predict the noise level of a hovering UAV in a bakery shop. In the scaled bakery model, a small volumetric sound source was developed and used to measure the acoustic transfer functions. In that case, the uncorrelated model compared well with measurement.