Numerical Simulation of the Aerodynamic Performance of the Backswept Blade of a Propeller at High Altitudes

Abstract

In high-speed situations, propeller efficiency drops rapidly after the design point is surpassed, and propeller performance deteriorates sharply; thus, high-altitude, long-endurance unmanned aerial vehicles (UAVs) cannot readily meet the design requirements of fast climbing and rapid maneuvering. The design method of the swept blade is investigated to solve this problem. The three-dimensional Reynolds averaged Navier-Stokes (RANS) equations are solved based on the periodic boundary conditions and multiple reference frame (MRF) models to simulate the aerodynamic properties of unswept and swept blades. The results show that the swept-blade propeller can provide a larger thrust than the unswept-blade propeller and that the velocity range with acceptable efficiency is extended after the design point is surpassed. The sweep design method used in this paper provides a reference for the propeller design of high-altitude, long-endurance UAVs.