Aerodynamic Design Optimization and Analysis of Ducted Fan Blades in DEP UAVs

Abstract

In order to reduce the dependence on fossil fuels, the concept of distributed electric propulsion (DEP) has been introduced. At present, there are a few studies on the small electric propulsion engines of DEP vertical take-off and landing (VTOL) UAVs. According to the design requirements of DEP VTOL UAV ducted fans, the aerodynamic design of a ducted fan is carried out in this paper. Firstly, the initial model is established by referring to theoretical derivations. Then, Bezier curves are used to control the mid-arc and thickness distributions of the blade profiles at different blade heights in order to realize the parameterization as design variables. Finally, the objective function that can represent the performance of the rotor is selected, and a multi-objective genetic algorithm is used to optimize the performance. The optimal results are obtained, and the aerodynamic characteristics are analyzed. Compared with the initial model, the total pressure ratio and isentropic efficiency of the optimized model are increased by 5.3% and 7.8%, respectively, reaching 1.20 and 90.37%. Meanwhile, the aerodynamic performance of the optimized model is improved, indicating that the performance of the rotor is significantly enhanced and that the design task is completed.