Research on Longitudinal Static Stability for VFSW Tailless Configuration UAV

Abstract

The Variable Forward-Swept Wing (VFSW) Tailless configuration UAV can well satisfy multipurpose demands. However, this kind of unconventional morphing aircraft lacks tail, which brings great challenge to stability analysis. The connatural aero-elasticity divergence and the strong aerodynamic coupling as well as many uncertain factors in mechanical environment, give the VFSW Tailless configuration UAV complicated dynamic characteristics. During the process of transformation, the variation of dynamic shape will inevitably lead to the variation about aerodynamic center and barycentre positions of airplane, then make the angle of attack static stability margin variable, and directly influence stability of aircraft. On the basis of introduction of the VFSW Tailless configuration UAV, according to its geometric shape, positions of aerodynamic center and barycentre, in different states with different forward-swept angle, were calculated, so as to obtain variation curve of longitudinal static stability margin, which provided preferences for dynamics analysis, position of barycentre adjustment and design of flight control system (FCS).