本研究先行使用風能解析及應用軟體(Wind Atlas Analysis and Application Program, WAsP) 針對海洋竹南離岸式風力發電場進行風能效率評估的前驅模擬，再利用大渦漩模擬(Large eddy simulation, LES)進行在特定風向下，不同風速對發電效率以及尾流效應的探討。由於計算流體力學(Computational Fluid Dynamics, CFD)的運算時間較長，因此我們透過WAsP軟體進行模擬，分析海洋竹南離岸式風力發電場在各個風速下全方向的風能效率以及尾流損失，找尋具代表性的風向為何。由於WAsP軟體說明風向45度之風機發電效率較差且其為風電場的盛行風向，因此選定風向45度搭配6、9、12和15 m s^(-1)之風速，共四種案例進行大渦漩模擬計算，同時引入風機的模組參數，將風通過風機後產生的作用力導入流場的動量方程式中，藉此計算速度場的相關參數並進一步得到整體風電場的發電量輸出及尾流特性。模擬結果表示，海洋竹南離岸式風力發電場受東北風(即45度風向)吹拂時，部分風機在流向方向上呈現對準配置(aligned configuration)，此時風機的流向間距對於下游風機的發電量有著重要的影響。隨著入流風速的增加，風機尾流效應會逐漸降低。當速度超過風機設定之額定風速時，僅剩後排風機可以觀察到尾流效應，此時發電效率得到顯著的提升。此外，當入流風速較低時，可觀察到部分後排風機會被前排風機之尾流區域包覆，導致推力係數下降，當入流速度接近額定風速則不再出現此現象，可說明風速上升可以增加風機的性能穩定。

This study first uses Wind Atlas Analysis and Application Program (WAsP) to conduct a precursor simulation of wind energy efficiency evaluation for Formosa 1, then uses large eddy simulation (LES) to discuss the power generation efficiency and wake effects under specific wind direction and different wind speeds. WAsP shows that wind turbines with a wind direction of 45 degrees have lower power generation efficiency, and occurs more frequently in wind farms. Therefore, this study chose the wind direction of 45 degrees with the wind speed of 6, 9, 12 and 15 m s^(-1) for simulation. The simulation results show that when Formosa 1 is affected by the wind direction at 45 degrees, some turbines have an aligned configuration in the streamwise direction. At this time, the streamwise spacing has an important influence on the power generation of downstream turbines. As the wind speed increases, the turbine wake effect gradually decreases. In addition, when the wind speed decreases, it can be observed that part of the rear turbines is covered by the wake area of the front turbines, resulting in the thrust coefficient reduced. When the inflow speed is close to the rated wind speed, this phenomenon will no longer occur, which indicates that the increase in wind speed can improve the performance stability of the turbine.

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