Scaled wind turbine setup in a turbulent wind tunnel

Wind tunnel experiments with scaled model turbines are a viable complement to field tests and simulations. The scaling of a 5 MW reference turbine with the aim of maintaining the design tip speed ratio and lift distribution is introduced. The machine, named MoWiTO 1.8 (Model Wind Turbine Oldenburg 1.8 m), is described in this paper and the setup in the WindLab wind tunnel of the University of Oldenburg, featuring an active grid, is described. Based on aerodynamic simulations in a turbulent wind field flow, the calculated aerodynamic loads of the reference turbine and the scaled model are compared. Furthermore, the aerodynamic characterization of the machine is presented, with focus on power and thrust coefficients and sensitivity to changes in the Reynolds number. It is shown, that with the chosen approach many attributes of the reference turbine can be scaled into the controllable wind tunnel environment.