非定常气动力对垂起固定翼无人机动力学的影响

Due to the complicated structure of the VTOL fixed-wing UAV, it is difficult to establish its dynamic model by the method of single rigid modeling and obatin the unsteady aerodynamic forces by numerical simulation. In order to solve these problems, considering the effects of hysteresis loop, the hysteresis loop of airfoil is simulated by CFD. Then, the unsteady aerodynamic forces model of the process from the taking-off to cruising of the UAV by the ONERA equation is established. Finally, based on the multi-body dynamics method, the UAV, as a multi-rigid system, is divided into wing, fuselage, rotor and rudder surface. The dynamic model of the UAV is deduced and established by Kane equation. Through the results of numerical simulation, it can he found that the multi-body dynamics method is suitable for the modeling of this kind of UAV. The hysteresis loop has a clamping influence on the pitching of UAV, and there are 8% difference between the UAV vertical taking-off velocity with unsteady aerodynamic forces and that without unsteady aerodynamic forces, and 40% difference of rising velocity between them when the UAV accomplished the process from vertical taking-off to flat flight.