Nonlinear aeroelastic stability analysis of a two-stage axially moving telescopic wing by using fully intrinsic equations

During the process of span extension for an aircraft wing equipped with a telescopic morphing mechanism, the wing aspect ratio increases, and hence, the geometrical nonlinearities might become more significant. In this regard, this paper aims to investigate the effect of structural nonlinearity on the aeroelasticity of span morphing wings using the exact fully intrinsic equations for the first time. Furthermore, the effects of various parameters such as thrust force, engine location, chord size, flight altitude, initial angle of attack, and overlapping mass on the aeroelasticity of the wing are studied. The applied aerodynamic loads in an incompressible flow regime are determined using Peters’ unsteady aerodynamic model. In order to check the stability of the system, first the resulting nonlinear partial differential equations are discretized by using the central finite difference method and then linearized about the static equilibrium. Finally, by obtaining the eigenvalues of the linearized system, the stability of the wing is evaluated. It is observed that by using the fully intrinsic equations, the instability of the axially moving telescopic wing can be determined more accurately. Moreover, the results show that the morphing length and overlapping mass have significant effects on the aeroelastic stability of the telescopic wing.