Aerodynamic response of a floating wind turbine scale model with inclusion of reference control functionalities

Abstract

Abstract. Design and verification of control strategies for floating wind turbines often makes use of aero-hydro-servo-elastic modeling tools. Aerodynamic loads calculation in these tools has been recently validated against experiments not including active wind turbine control. This work investigates the aerodynamic response of a floating wind turbine scale model with active control and platform pitch motion. This is done in wind tunnel testing and with modeling of the scaled system in the offshore tool OpenFAST. A control design framework is developed to include the reference wind turbine controller ROSCO in the wind tunnel experiment. With platform pitch motion, the turbine aerodynamic response is predicted by the numerical model with different accuracy depending on the turbine control regime. Below rated wind, oscillations of aerodynamic torque in simulations are of lower amplitude than in the experiment, also when dynamic inflow is considered in the aerodynamic model. Above rated wind, where the turbine is controlled with collective blade pitch actuation, the response is not quasi-steady, and differences between the experiment and simulation are larger than in below-rated wind, in particular for phase with respect to motion.