Aerodynamic-interference optimization design for a multirotor UAV based on flight-mechanics analysis

Abstract

Aerodynamic interference among rotors strongly affects the flight performance and power consumption of multirotor unmanned aerial vehicles (UAVs). This paper develops a flight-mechanics model that couples dynamic inflow theory, a rotor vortex-tube wake model, blade element theory (BET), and UAV rigid-body dynamics to efficiently evaluate the influence of rotor-rotor aerodynamic interference on power consumption. The model is validated against experimental rotor data and then used to analyze the effects of rotor spacing. The results show that power consumption can be reduced by increasing the front-rotor lateral spacing and the front-rear longitudinal and vertical spacings, while reducing the rear-rotor lateral spacing. A wide-front, narrow-rear, low-front, and high-rear layout is therefore proposed. At the cruise speed of 15 m/s, the optimized layout reduces total rotor power by 10.82% and 10.30% compared with typical H-type and X-type layouts, respectively.