Aerodynamic Characteristics Analysis of Takeoff Transition Mode for Tilting Wing Unmanned Aerial Vehicles at Different Pitch Angles

The tilting wing UAV, as a tilting powered vertical takeoff and landing aircraft with both vertical takeoff and landing and high-speed cruise capabilities, can flexibly switch between helicopter mode and fixed wing mode. In the tilt transition mode, parameters such as flight attitude angle, forward flight speed, and tilt speed will continue to dynamically change with the change of tilt angle. The multi-degree-of-freedom coupling effect leads to strong unsteady aerodynamic characteristics of the entire machine. The dynamic characteristics of multi-parameter strong coupling pose a severe challenge to the control stability of aircraft and become a difficult point in the design of tilt wing unmanned aerial vehicle control systems. This article uses the unsteady momentum source method to numerically calculate and analyze the takeoff transition modes of a tilting wing unmanned aerial vehicle at a tilt speed of 20˚/s, uniform acceleration inflow, and 0˚, −2˚, and −5˚ pitch angles. In order to grasp their aerodynamic interference laws and provide reference for the design and control theory research of such aircraft.