Two-dimensional transonic aeroservoelastic computations in the time domain

A computational method to perform transonic aeroelastic and aeroservoelasti c calculations in the time domain is presented, and used to predict stabili ty (flutter) boundaries of 2-D wing sections. The aerodynamic model is a ce ll-centred finite-volume unsteady Euler solver, which uses an efficient imp licit time-stepping scheme and structured moving grids. The aerodynamic equ ations are coupled with the structural equations of motion, which are deriv ed from a typical wing section model. A control law is implemented within t he aeroelastic solver to investigate active means of flutter suppression vi a control surface motion. Comparisons of open- and closed-loop calculations show that the control law can successfully suppress the flutter and result s in an increase of up to 19 per cent in the allowable speed index. The eff ect of structural non-linearity, in the form of hinge axis backlash is also investigated. The effect is found to be strongly destabilizing, but the co ntrol law is shown to still alleviate the destabilizing effect. Copyright ( C) 2001 John Wiley & Sons, Ltd.