Dynamic coupling of wake added turbulence and array effects: nonlinear impacts on power performance and fatigue damage of 22 MW floating offshore wind turbines

Wake effect on the power generation and dynamic load of wind turbine becomes more pronounced with the increasing scale of wind farms, especially for downstream offshore floating wind turbine subjected to wake-wave-current interactions. This study investigates the influence of wake meandering, wake added turbulence, and array effect on the power performance and fatigue damage of floating wind turbine through improved dynamic wake meandering model, incorporating variations in inflow velocity, turbulence intensity, and axial distance. The IEA 22 MW reference wind turbine with the largest rated power available at present was employed. Results indicate that the wake added turbulence effect partially offsets the power benefits induced by enhanced radial momentum mixing from the wake meandering effect. However, the coupled effect of wake meandering and wake added turbulence makes a greater contribution to fatigue damage than the wake meandering effect alone. For an inflow velocity of 11 m/s and a turbulence intensity of 0.16, wake meandering increases the short-term damage rate at the blade root by 23.62%, while a further 19.23% increase is induced by wake added turbulence. A symmetry axis with counterclockwise rotation is observed in the short-term DES distribution at the blade root as inflow velocity and turbulence intensity increase. Moreover, the marginal effect of rotor power is diminished as the axial distance increases. The total rotor power of the turbine cluster increases by 19.56% when the axial distance expands from 4D to 7D, but only by 12.06% when expanding further from 7D to 10D. Better insights for the performance evaluation of floating wind turbine within offshore wind farm can be provided.