Design, performance optimization, and experiments of a tail-propeller layout multi-rotor UAV

As a new type of aerial transportation, eVTOLs are regarded as a highly promising aircraft category for future urban mobility, owing to their structural simplicity and environmental benefits. However, improving the aerodynamic performance including flight time and flight range at high speeds is one of the key issues in the practical application of eVTOLs. This paper proposes a new aerodynamic layout based on a tail-propeller configuration. Different from multi-rotor configurations, the tail-propeller UAV utilizes a propeller at the rear to provide the thrust required for forward movement, thereby enhancing the efficiency of the main propeller and consequently improving the performance of rotor UAVs. Firstly, this paper introduces the layout and integrated design method of the tail-propeller UAV, and establishes the dynamic model. Secondly, wind tunnel tests are designed to fit and validate the model, and the mechanism for improving the efficiency of the main propeller is derived. Finally, an optimization design method for the tail-propelled UAV is proposed and validated through actual flight tests. The results show that compared with multi-rotors, tail-propeller UAVs demonstrate superior flight performance and can fly at a speed of 108 km/h for 55 minutes. The problem of short flight time at low speeds caused by the introduction of tail propeller has also been effectively solved through the α -tail-propeller aerodynamic layout.