Continuum Aeroelastic Model and Flutter Analysis for a Variable-span Morphing Wing

A linear aeroelastic continuum model for a variable-span wing is developed. Considering the fixed inboard part and the movable outboard part of the wing, a stepped Euler-Bernoulli beam with three jumped discontinuities in its spatial span is used for structural modeling. The dynamic analysis of stepped beam is introduced by a dimensionless form. The time-domain aerodynamic forces are calculated by a reduced-order unsteady vortex lattice model. Then the first-order state-space aeroelastic formulations are built by using the Galerkin method. The impact of the different wing configurations is of particular interest for understanding the fundamental aeroelastic behavior of variable-span wing. To clarify the implementation of the proposed method, a simple variable-span wing with the basic parameters of the Goland wing is studied, and numerical simulations are provided to demonstrate the flutter speeds and frequencies for different wing configurations.