Quantitative impact of combining blowing and suction flow control on a floating offshore wind turbine aerodynamic performance under the surge motion

The dynamic stall induced by platform surge motion significantly reduces the output power of a floating wind turbine and shortens the machine's operational lifespan. This work examines the impact of a D-SFJ active flow control, featuring two suction slots on the suction side and two injection slots near the trailing edge on the pressure side, on the aerodynamic performance of the NREL 5 MW reference wind turbine during surge motion. Numerical simulations are conducted using the Unsteady Reynolds-Averaged Navier-Stokes (URANS) method with the shear stress transport (SST) k-ω turbulence model and the overset mesh technique is performed. The findings confirm that the surge motion dynamically enlarges the flow separation region over the blade surface, with a maximum increase of 164.29 % in comparison to the wind turbine in a fixed state. The control device implemented in the entire rotor can enhance the aerodynamic performance and improve the flow pattern throughout a single surge cycle. For instance, at an inflow of 7 m/s and a jet strength of 0.01, the D-SFJ device yields a 4.82 % increase in average net output power and the separation area can be reduced by 54.68％ compared to the baseline rotor.