Effects of tide-induced variation of hub height on the power of wind turbine array: A LES study

Offshore wind farms are typically constructed in coastal waters with large tidal range. However, the influence of tide-induced variations of hub height on turbine wake evolution has rarely been investigated. This study employs large eddy simulation to investigate tidal effects on wake evolution and power output. Results indicate that an 8 m reduction of water level enhances power generation in the first turbine by 3.5 %, with even greater increases of 5.8 % and 5.5 % observed in following downstream turbines. These findings suggest that wake interactions amplify the impacts of tide-induced changes of water level. Mechanistic analysis attributes this phenomenon to enhanced turbulent transport of mean kinetic energy at the bottom of wake during low tide, which accelerates wind speed recovery. Simulations conducted across varying tidal levels (−6 to 6 m) reveal that power losses during high tide exceed gains from low tide, indicating an asymmetric feature. Results obtained under different wind speed (6–12 m/s) confirm that tidal effects consistently influence turbine power output. A tide-integrated correction scheme is proposed for analytical wake models to improve power prediction accuracy during tidal cycles. This study contributes to enhancing offshore wind power forecasting and provides critical insights for optimizing hub height design.