Unsteady aeroelastic response of rigid airfoils with nonzero angles of attack

The effects of varying the angle of attack on the flutter speed and limit cycle oscillations of an aeroelastic system are investigated. This system consists of a rigid airfoil supported by linear springs that undergoes plunging and pitching motions. The Unsteady Vortex Lattice Method (UVLM) is used to model the aerodynamic loads. To solve simultaneously and interactively the governing equations, an iterative scheme based on Hamming's fourth order predictor-corrector model is employed. The effects of the angle of attack on the dynamic response including the flutter speed and ensuing limit cycle oscillations are investigated. The results show that the flutter speed increases as the angle of attack is increased. It is also determined that increasing the preset angle of attack results in a decrease of the amplitudes of the limit cycle oscillations.