DNS of Actuator Disk Arrays in Ekman Boundary Layers: Preliminary Results

Abstract

The power output of large wind farms is limited by the downward flux of kinetic energy through the atmospheric boundary layer, as ultimately all available power at turbine altitude is exhausted. This becomes relevant when the power extracted per unit area is sufficiently large, and the atmospheric boundary layer is significantly affected by the wind farm. Such coupling is therefore relevant to the design of farms, in terms of the spacing between turbines (typically roughly 5 diameters) and their resistance level (as compared with the Betz setting).