State-Space Representation of Instationary Two-Dimensional Airfoil Aerodynamics

In the aero-elastic analysis of wind turbines based on blade element theory, the need to include a model of the local, two-dimensional instationary aerodynamic loads, commonly referred to as dynamic stall has become obvious in the last years. In this contribution we describe an alternative choice for such a model. Its derivation is governed by the flow physics, thus enabling interpolation between different profile geometries. To facilitate aeroelastic stability and sensitivity investigations, the original model is changed into state-space form, i.e. a system of differential equations. The transformation into state-space form is validated with numerical calculations.