Mission-Oriented Propulsion System Configuration and Whole Aircraft Redundancy Safety Performance for Distributed Electric Propulsion UAVs

Distributed electric propulsion has emerged as a prominent research area in aerospace engineering. The capabilities of shorter takeoff distance and efficient cruise flight are the important advantages of a distributed propulsion UAV over a traditional fixed-wing UAV, and the composition of multiple motors can significantly improve the safety of the aircraft. This paper proposed an overall design method for the power system of the distributed propulsion UAV with the mission requirements as inputs, using the Actuator Disk Theory and Vortex Lattice Method to analyze the aerodynamic performance corresponding to different propeller numbers and layouts, and combining with the BP neural network to obtain the optimal propeller position. Meanwhile, the Linear Quadratic Regulator method was employed to analyze different configurations of UAVs, and the effects of the number of propellers and thrust redundancy on their safety were explored. The parametric study revealed that as the number of propellers increased, the optimal horizontal distance between the propeller and the leading edge of the wing gradually decreased (closer to the wing), and the vertical distance also gradually decreased (lower to the wing). The safety study revealed that when the number of propellers reached eight or more, the UAV could maintain stable flight with a probability exceeding 70% even when two or three propulsion components fail. The computational method and safety analysis for different propeller combinations studied in this paper feature high efficiency and low computational consumption, which can provide an effective reference for the overall design phase of distributed propulsion aircraft.