This study aims to optimize the acoustic power level of the APC11x4.7SF unmanned aerial vehicle (UAV) propeller using the Taguchi design of experiment approach. This research focuses on enhancing UAV propeller aerodynamic performance simultaneous with reduction in acoustic power level.
This study was conducted in two stages. Initially, the blade airfoil (E63) optimization was performed in terms of its maximum camber, maximum camber position and maximum thickness. Later on, three-dimensional blade shape optimization was performed, where the pitch angle of spanwise control stations is defined as the primary geometric parameter. The influence of each parameter on aeroacoustic performance is quantified using the Taguchi method, and Computational Fluid Dynamics (CFD) investigation was used to verify the results upon estimated optimal conditions.
For the proposed models, the acoustic power level (APL) of the propeller at optimal conditions is reduced to 109.14, 109.71 and 108.54 dB, compared to the baseline model with 113.50 dB. In addition, the shape optimization was resulted in a 0.049 N increase in thrust and a 4.36 dB reduction in APL. A thrust increase of 4.14% and a noise reduction of 3.84% were achieved, demonstrating the aerodynamic and acoustic effectiveness of the proposed design. These results demonstrated significant improvements in both acoustic performance and thrust compared to the initial propeller design.
This study provides a novel application of the Taguchi design of experiment approach to aeroacoustic optimization of a UAV propeller, integrating both two-dimensional airfoil and three-dimensional shape optimization. Moreover, the effectiveness of the design of experiment and CFD methods combination for achieving simultaneous improvements in acoustic power levels and thrust has been proposed, together with offering valuable insights for UAV propeller design advancements.
