Geometrically exact vortex lattice and panel methods in static aeroelasticity of very flexible wing

Geometrically exact vortex lattice method and panel method are presented in this paper to deal with aerodynamic load computation for geometrically nonlinear static aeroelastic problems. They are combined with geometrically nonlinear finite element method through surface spline interpolation in the loosely-coupled iteration. From the perspective of theoretical research, both vortex lattice method and panel method are based on the full potential equation and able to model the deflection and twist of the wing, while vortex lattice method is based on the thin airfoil theory, and panel method is suitable for thick wings. Although the potential flow equation is linear, the introduction of geometrically exact boundary conditions makes it significantly different from the linear aeroelastic analysis. The numerical results of a high aspect ratio wing are provided to declare the influence of large deformation on nonlinear static aeroelastic computation compared with linear analysis. Aeroelastic analyses based on geometrically exact vortex lattice method and panel method are also compared with the results of computational fluid dynamics/computational structural dynamics coupling method and the wind tunnel test data. The nonlinear static aeroelastic analysis agrees with the measurement even in considerably large deformation situations.