Wind turbine wake properties: Comparison between a non-rotating simplified wind turbine model and a rotating model: Fid-Bau Portal

Wind turbine wake properties: Comparison between a non-rotating simplified wind turbine model and a rotating model

Aubrun, S. / Loyer, S. / Hancock, P.E. / Hayden, P.

Abstract Experimental results on the wake properties of a non-rotating simplified wind turbine model, based on the actuator disc concept, and a rotating model, a three-blade wind turbine, are presented. Tests were performed in two different test sections, one providing a nominally decaying isotropic turbulent inflow (turbulence intensity of 4% at rotor disc location) and one providing a neutral atmospheric boundary layer above a moderately rough terrain at a geometric scale of 1:300 (determined from the combination of several indicators), with 13% of turbulence intensity at hub height. The objective is to determine the limits of the simplified wind turbine model to reproduce a realistic wind turbine wake. Pressure and high-order velocity statistics are therefore compared in the wake of both rotor discs for two different inflow conditions in order to quantify the influence of the ambient turbulence. It has been shown that wakes of rotating model and porous disc developing in the modeled atmospheric boundary layer are indistinguishable after 3 rotor diameters downstream of the rotor discs, whereas few discrepancies are still visible at the same distance with the decaying isotropic turbulent inflow.

Highlights • Experimental results on the wake properties of a non-rotating simplified wind turbine model and a rotating model are presented. • Tests were performed in two different inflows, decaying isotropic turbulent inflow and modeled neutral atmospheric boundary layer. • Pressure and high order velocity statistics are compared in the wake of both obstacles and show strong similarities. • The simplified model is able to reproduce the wind turbine far-wake in highly turbulent flows, as in most atmospheric flows.