Spectral coherence in wind turbine wakes

Abstract Spectral coherence in the wake of a wind turbine situated in a wind farm has been investigated. Results are presented for lateral coherence at two heights with 5 m separation and vertical coherence at 13 m separation at different downstream stations in the wake. Also presented is the decay of turbulence generated by the wake. The results show that turbulence from the wake is still noticeable 15 diameters from the turbine, lateral coherence in the near-wake is decreased relative to conventional models, but from 8 rotor diameters on, the lateral coherence seems unaffected by the wake. The vertical coherence shows only little influence by the wake.