Multi-Disciplinary Design and Experimental Verification of Low Noise Aircraft Propellers

In order to reduce the noise of aircraft propellers，multi-disciplinary design and experimental verification for a certain low noise aircraft propeller that comprehensively considers aerodynamic，noise and struc⁃ tural strength were carried out. A joint algorithm for propeller aerodynamic/aeroacoustic performance was pro⁃ posed，in which lifting surface theory based on the vortex lattice method was applied for propeller aerodynamic performance calculating，and Hanson frequency domain far-field noise calculation method was employed in pro⁃ peller far-field noise evaluation. Both of these methods were validated with experiments and formed as a joint opti⁃ mal algorithm. Distribution of chord，blade angle and side sweep along the blade height were made as design vari⁃ ables for the optimization. The constraints of blade structural strength on design variables were fully considered. The objective was to maximize the noise reduction in the far field without sacrificing the propeller aerodynamic ef⁃ ficiency and thrust. The optimized blades were verified by the structural strength，which were centrifugal load ex⁃ periment，aerodynamic load experiment and dynamic characteristic experiment. The aerodynamic and aeroacous⁃ tic experiments were carried out in the aeroacoustic wind tunnel. The experimental results of the optimal propeller indicated similar aerodynamic performance with that of basic propeller. The far-field aerodynamic noise peak of the optimal propeller at the first-order discrete component of the design condition was reduced by 2.7dB. Noise re⁃ duction was up to 4dB under smaller thrust. A significant noise reduction at second-order discrete component were also observed. The method proposed in this paper meets the requirements of aerodynamics，acoustic and structural strength at the same time. © 2023 Journal of Propulsion Technology. All rights reserved.