Wind farms are typically composed of a single model of turbine with identical hub heights. The wind field behind the turbine in a wind farm has a lower mean wind speed and a greater turbulence intensity than the ambient wind field. As turbines get larger in size, the impact of wake interference between turbines becomes more substantial, particularly for floating wind turbines (FWT). FAST.Farm is employed to simulate a two semi-submersible FWT (5MW & 15MW) case with two different hub heights. The results demonstrates that wake effect has a noticeable influence on the movements and loads of downstream turbines.
Wind energy is a critical component of the growing renewable green energy industrial sector within the offshore energy sector. Generally, lower ocean surface roughness is related with increasing mean wind speeds. Wind resources are more plentiful in deep water where bottom-fixed offshore turbines are impractical. Floating wind turbines (FWTs) are a cost-effective way to gather wind energy in deep water. There are numerous floating wind farms in the development stage, as well as one that is operational, named Hywind Scotland. With the development toward deep ocean wind energy harvesting, understanding wake interaction between FWTs becomes increasingly critical.
When upstream air flows over a wind turbine, the mean wake velocity drops as the wake grows downstream of the rotor plane from energy extraction. The wake created by turbines has a direct detrimental effect on the performance and lifetime of downstream turbines. This is because a wake velocity deficit limits power output while increasing turbulence intensity in the form of a wake. Intensified turbulence may result in increased fatigue stresses on downstream FWTs. For downstream turbines, wake interactions enhance structural turbulence loading, hence raising fatigue loads and limiting turbine lifespan. Both wind farm power output and turbine lifetime are critical factors in evaluating wind energy's profitability. A deeper understanding of wake inference in the wind farm enables the identification of how interactions impact downstream turbines, which might result in increased turbine performance and lifespan via improved yaw control and micro-sitting placement. Figure 1 illustrates the wake phenomenon in the offshore wind farm.
