Major research outcome
- AIM Laboratory Led by Professor Sang Lee, Evaluation of Active Wake Mixing for Floating Offshore Wind Turbines with SOWFA-OpenFAST Coupling
- 관리자 |
- 2025-11-18 15:24:32|
- 225
- 2025-11-18 15:24:32|
Wake interaction remains one of the most critical challenges in offshore wind farm operation, as downstream turbines often experience diminished inflow velocity and elevated turbulence, leading to reduced power generation and accelerated structural fatigue. In pursuit of improved farm-wide efficiency, the AIM Laboratory at KAIST, led by Professor Sang Lee, has conducted a comprehensive numerical study using Large Eddy Simulation (LES) within the Simulator for Offshore Wind Farm Applications (SOWFA) coupled with OpenFAST.
Within this framework, researchers Yisehak A. Keflemariam and Moosarreza Shokati examined three active wake-mixing strategies: Dynamic Induction Control (DIC), Dynamic Individual Pitch Control (DIPC), and a higher-order DIPC tailored for floating platforms. The higher-order DIPC introduces multiple sinusoidal pitch components that collectively excite the wake at distinct frequencies, thereby amplifying tip-vortex instability and promoting enhanced wake recovery. This formulation extends established wake-mixing concepts by adapting them to the coupled aero-hydro-servo dynamics unique to FOWTs, offering a practical and physics-aware control approach suited to offshore environments.
The simulations reveal that frequency-tuned pitch excitation substantially energizes the near wake, accelerates vortex breakdown, and enhances entrainment of high-momentum air from the surrounding boundary layer. Among all control cases, the higher-order DIPC achieves the most significant improvement, with an average total power increase of approximately 7.9 percent relative to the baseline Greedy control, and about 2.3 percent higher than the conventional single-frequency DIPC, while maintaining acceptable load levels on the turbine and platform. Flow-field analyses using Proper Orthogonal Decomposition (POD) and Mean Kinetic Energy (MKE) flux further confirm that the higher-order DIPC strengthens energy transfer mechanisms and shortens the wake recovery distance.
Through the integration of LES and SOWFA-OpenFAST coupling, this research provides one of the most comprehensive evaluations of active wake control applied to floating configurations. The findings demonstrate that carefully tuned higher-order pitch modulation can improve wake mixing and downstream energy availability without compromising structural integrity. The AIM Laboratory’s work thus establishes a valuable computational and physical foundation toward next-generation wind farm applications.
https://doi.org/10.1016/j.enconman.2025.120552
Within this framework, researchers Yisehak A. Keflemariam and Moosarreza Shokati examined three active wake-mixing strategies: Dynamic Induction Control (DIC), Dynamic Individual Pitch Control (DIPC), and a higher-order DIPC tailored for floating platforms. The higher-order DIPC introduces multiple sinusoidal pitch components that collectively excite the wake at distinct frequencies, thereby amplifying tip-vortex instability and promoting enhanced wake recovery. This formulation extends established wake-mixing concepts by adapting them to the coupled aero-hydro-servo dynamics unique to FOWTs, offering a practical and physics-aware control approach suited to offshore environments.
The simulations reveal that frequency-tuned pitch excitation substantially energizes the near wake, accelerates vortex breakdown, and enhances entrainment of high-momentum air from the surrounding boundary layer. Among all control cases, the higher-order DIPC achieves the most significant improvement, with an average total power increase of approximately 7.9 percent relative to the baseline Greedy control, and about 2.3 percent higher than the conventional single-frequency DIPC, while maintaining acceptable load levels on the turbine and platform. Flow-field analyses using Proper Orthogonal Decomposition (POD) and Mean Kinetic Energy (MKE) flux further confirm that the higher-order DIPC strengthens energy transfer mechanisms and shortens the wake recovery distance.
Through the integration of LES and SOWFA-OpenFAST coupling, this research provides one of the most comprehensive evaluations of active wake control applied to floating configurations. The findings demonstrate that carefully tuned higher-order pitch modulation can improve wake mixing and downstream energy availability without compromising structural integrity. The AIM Laboratory’s work thus establishes a valuable computational and physical foundation toward next-generation wind farm applications.
https://doi.org/10.1016/j.enconman.2025.120552
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