Turbulence structures and entrainment length scales in large offshore wind farms

Abstract. The flow inside and around large offshore wind farms can range from smaller structures associated with the mechanical turbulence generated by turbines to larger indicative of mesoscale flow. In this study, we explore variation in dominant scales vertical entrainment above located North Sea, using data obtained a research aircraft. aircraft was flown upstream, downstream, farm clusters. Under neutrally stratified conditions, there is high ambient atmosphere an elevated energy dissipation rate compared stable conditions. intensity small-scale increased downstream farm, it prevails over fluctuations. But stratification, are not only upstream but also downstream. We observed that flux horizontal momentum main source recovery farms, strongly depends on magnitude length velocity component. 20 ∼60 m all stratification strengths, wake these 10 ∼100 under near-neutral stratification. For negligible even just 2 km farms. significant lateral especially which suggests do satisfy conditions “infinite farm”.