A quasi-linear approach for solving aeroelastic problems involving aerodynamic and structural nonlinearities

A coupled framework for addressing the nonlinear aeroelasticity problem is introduced. A two-degree of freedom (pitch and plunge) two-dimensional using has been used for demonstrating the framework. The structural analysis is capable of addressing both linear and nonlinear (hardening nonlinearity pitch mode, free play nonlinearity in pitch and plunge mode) effects. Both subsonic and transonic regimes are considered. The unsteady aerodynamic flow-field (for calculating aerodynamic loads) is evaluated using a 3-D Navier-Stokes solver (CFL3D 6.1). Structural nonlinearities are incorporated in the solver in a quasi-nonlinear fashion. The present calculations include aerodynamic nonlinearities as well as those mentioned above. The effect of including the nonlinear effects in the analysis has been studied.