关键词: 变体飞机, Z型翼, 多体动力学, 纵向, 建模, 仿真

Abstract: The longitudinal multibody dynamic modeling and simulation of a Z-wing morphing aircraft in the wing morphing process is studied. When the wing is morphing, the wing area, moments of inertia, locations of aerodynamic center and center of gravity alter considerably, and these will change the dynamic characteristics of the aircraft. The six degree of freedom nonlinear dynamic functions of the morphing aircraft in the morphing process are derived. In addition, the decoupled longitudinal dynamic function is presented by simplification. The result of numeric simulation of aerodynamics in the wing folding process shows that the aerodynamics at various folding velocities is approximately the same. On condition that the wing fold angular velocity is small and the unsteady aerodynamic effect can be ignored, the longitudinal responses of the morphing aircraft in different wing fold angular velocities are numerically simulated by quasi-steady aerodynamic supposition. And the rules of how the dynamic characteristics are affected by the shift of center gravity position and variation of aerodynamics are investigated. The results show that the key factor which influences the morphing aircraft dynamic response in wing folding is the variation of aerodynamics. When the wing fold is completed, the flight velocity and angle of attack of the morphing aircraft will become larger, and its flight altitude will become considerably lower.

Key words: morphing aircraft, Z-wing, multibody dynamics, longitudinal, modeling, simulation