Experimental analysis of wakes in a utility scale wind farm

The measurements of the near (less than three rotor diameter) and far wakes (unto eleven rotor diameter) in a utility scale wind farm are described. The high spatial and temporal resolution measurements are made with an instrumented drone that is equipped with a suite of sensors. These measurements detail for the first time at full-scale Reynolds number conditions, the evolution and breakdown of tip vortices that are characteristic of the near wake and the turbulent mixing and entrainment of more energised flow that are distinctive in the far wake. Comparisons of these measurements to recently developed wake prediction models highlights how these measurements can support further model development.