Numerical analysis of unsteady aerodynamics of floating offshore wind turbines

The unsteady aerodynamics of a scaled model floating horizontal-axis offshore wind turbine is investigated numerically. Different aerodynamic models are used to analyze the complex unsteady flow, namely models based on unsteady Reynold-Averaged Navier-Stokes equations, free vortex wake and blade element momentum theory. The wind turbine base is subjected to imposed sinusoidal surge oscillations to reproduce the motions of the floating platform. The aerodynamic response of the rotor and the wake unsteadiness are investigated, while an evaluation of the numerical models is performed with help of wind tunnel data.