CFD Validation of Scaled Floating Offshore Wind Turbine Rotor

Abstract

Offshore wind turbines are lucrative than land based turbines for its high and consistent wind speed. Since the floating wind turbines are economical than gravity based or fixed bottom type wind turbines, offshore wind industry is exploring all possible ways to adopt well established oil and gas floating platform technologies. Unlike fixed bottom wind turbines, floating platform is subjected to complex motions in all 6 degrees of freedom that introduces new challenges in predicting the aerodynamic forces on the rotor. The conventional approach to determine the aerodynamic forces is not applicable for offshore floating turbines that is subjected to hydrodynamic and all other forces. The current study is focused on computationally validating the scaled model of NREL 5MW wind turbine that is experimentally investigated for various frequencies of platform surge motions at University of Strathclyde. The thrust forces and rotor torque are computed by numerically simulation and compared with experimental outcome showing a good agreement in the trend. The minor deviation in the aerodynamic forces is attributed to the higher prediction of lift and drag forces by XFOIL.