Numerical analysis and aeroacoustic optimization of a uav propeller using computational fluid dynamics

Unmanned aerial vehicles (UAVs) have become widespread in various industries (agriculture, search and rescue and observation, etc.). They offer efficient and versatile solutions. With increasing use, their effects on human and environmental health have become a subject of research. Noise emissions in the environment close to the society have a significant negative impact on the residents. A point to be considered is to reduce the noise emissions generated by the propeller blade design and propeller operation. Pressure fluctuations in UAV propeller blades, vortexes formed at the blade tips and turbulence effects formed behind the blade can cause noise. This noise control is focused on considering the design factors. In this thesis study, an improvement study was carried out in the aerodynamic performance of the blade section geometry. Then, the effect of the blade angle on the acoustic power level was investigated through the aeroacoustic optimization study of the 3D propeller geometry of the verified method. NACA4412 and E63 were used as blade section profiles, and a 2-blade propeller (APC 11x4,7SF) with 280 mm diameter was used as the propeller model. Blade section geometries and propeller model were created using the ANSYS Fluent program Computational Fluid Dynamics (CFD) method. While the aerodynamic performance (lift-drag ratio) ratio of the blade section geometry was examined, the acoustic power level of the propeller model was examined. While Taguchi L9 orthogonal array was used for the blade section geometry, Taguchi L27 method was used for the propeller, an optimization study was carried out in order to obtain optimum aerodynamic performance for the blade section geometry and optimum aeroacoustic performance for the propeller model. As a result of the section and shape optimization study, it was shown that a decrease of at least 4,36 dB and at most 7,126 dB could be achieved in the propeller acoustic power level with some loss of thrust.