Aerodynamic Investigation for a Propeller-Induced Lift-Enhancing Vertical Take-Off and Landing (VTOL) Configuration

Difficulty in thrust-matching between the cruise and vertical take-off and landing (VTOL) phases is one of the prominent issues faced by conventional VTOL fixed-wing drones. To address this issue, a propeller-induced lift-enhancing (PILE) biplane wing VTOL configuration is proposed with the goal of lift enhancement on the wing during the no-forward-speed VTOL phase. Numerical simulation methods are used to study and analyze the aerodynamic characteristics of this configuration in the cruise and VTOL phases. The results show that the favorable inducing effect of the propeller makes the PILE configuration have a good effect of increasing lift and reducing drag compared with a single wing of the same area during the cruise phase, improving the lift-to-drag ratio by 7.27%. During the VTOL phase, the optimal tilt angle of the propeller for the PALE configuration is 70°, matched with an installation angle of 5° for the aided wing. This parameter combination balances the total drag while also achieving a lift-to-thrust ratio of 1.12. As a result, the required thrust of the propeller is reduced under the same take-off weight, which helps to alleviate the thrust-matching problem and enables VTOL with a smaller power cost.