Dynamic Stall and Stall Flutter Simulations for a 2D Airfoil Using Viscous-Inviscid Coupling

An interactive boundary layer model has been developed and coupled with a pitch plunge airfoil in 2d in order to solve the unsteady flow around the airfoil when undergoing light dynamic stall. The inviscid problem is solved by means of a panel method, by the discretization of the airfoil into vortex panels. The boundary layer is solved in a mixed manner, starting the solution in a direct way by imposing the external velocity and continuing it in an inverse way by imposing the displacement thickness. The solution of the boundary layer equations is carried out using a finite volume scheme. Viscous-inviscid coupling is preformed through the imposition of a permeation velocity on the skin panels of the airfoil and the addition of a free wake at each separation point.