Abstract: A nonlinear aeroelastic analysis method using computational fluid dynamics/computational structure dynamics (CFD/CSD) is presented and applied to the nonlinear flutter and limit-cycle-oscillation (LCO) research of a cropped delta wing. This computational method couples a nonlinear finite element method (FEM) model with a CFD solver by using a high-fidelity interface interpolation, and is capable of investigating aeroelastic problems with both structural and aerodynamic nonlinearities. The structural analysis is based on a quadrilateral flat-shell element and an updated Lagrange (UL) formulation, which can be employed to model geometric nonlinearities arising from large deflections. With the Navier-Stokes (N-S) equations as the control equations, a finite volume CFD solver is formulated to calculate transonic aerodynamics. The nonlinear flutter calculation demonstrates the validity of the presented method. Finally the cropped-delta-wing LCO is computed, and the calculation precision is obviously better than the existing results.

Key words: aeroelasticity, CFD/CSD, limit-cycle-oscillation, large deflection, transonic