Numerical and Experimental Study on Vertical Takeoff and Separation of the Compound Aircraft

The traditional technical solution to achieve vertical take-off of the fixed-wing aircraft is adding power components, which will inevitably increase the weight of the aircraft. This paper proposes a compound flight scheme to achieve vertical take-off for the fixed-wing aircraft, using the carrier aircraft with vertical take-off capability to carry the target aircraft. Compared with the vertical take-off performance of a single aircraft, the present scheme enables the target aircraft to have a larger carrying capacity and longer flight distance. In order to verify the feasibility of the current scheme, this paper first investigates the steady aerodynamic performance of the compound aircraft and the dynamical separation process by computational fluid dynamics simulation. The steady lift coefficient of the compound aircraft during the acceleration stage and the unsteady aerodynamic force during the separation stage are obtained and analyzed. Next, an unmanned aerial vehicle (with vertical take-off and horizontal acceleration capabilities) is designed specifically, and the flight experiments of the vertical take-off and separation processes are conducted. Successful separations are achieved many times in the flight tests, which validate the feasibility of the present scheme.