DESIGN FOR ACTIVE FLUTTER SUPPRESION AND MODEL VERIFICATION
The article deals with developing a mathematical model of non-rigid aircraft lifting surface with control surface controlled by pilot and supplementary control surface driven by control law. The purpose of this model is to determine if such as concept of control surface and supplementary control surface can be used for active flutter suppression on an aircraft structure. The supplementary control surface is placed next to the control surface at outboard side. The lifting surface is representing by an airfoil placed at 70% of a wing span.
A structural model is developed by means of Lagrange differential equations of second kind. Theodorsen model of thin oscillation airfoil with control surface is used for unsteady aerodynamic. Duhamel’s integral of Wagner function is carried out for transformation of unsteady aerodynamic to a time domain. The mathematical model is present in state space representation. There is exemplification of the critical flutter velocity calculation and a dynamical response of the structure. The supplementary control surface for flutter suppression with simplified model is added. Closed-loop feedback control system is formed and a several control laws are presents. The verification of open-loop model is done on behalf of the critical flutter speed comparison with FEM software for flutter analysis MSC.Nastran and flutter analysis program developed at CTU in Prague. The article also presents work on an experimental verification of the open-loop model in aerodynamic tunnel.