離岸風電場比陸域風電場更具優勢與潛能，但海上環境條件如颱風、波浪及海流等影響亦比陸域環境嚴苛。台灣海峽平均觀測風速高於國外已開發之離岸風電場，具有良好發展潛力，但台灣位於地震帶且多颱風侵襲，風險亦較其他離岸風電場高。為確保國內離岸風機的運轉安全及可靠性，分析與評估風機支撐結構是否得以承受場址特定環境條件(Site Specific Conditions)包括極端風況、海況及地震等衝擊，勢必成為未來離岸風電場建置前之重要工作項目。 本研究透過Splash3D模式進行三維數值模擬與分析，求解離岸風機在已知極端事件下受波浪及海流衝擊之承載力。Splash3D模式以美國國家實驗室（Los Alamos National Laboratory, LANL）所發展之Truchas模式為基礎進行研究與相關功能開發，模式可同時求解複雜且破碎之自由液面與結構物受力之動態過程，其以部份網格法（Partial-cell Treatment）於計算域中建構風機基礎，並用不規則網格包覆結構、配置數值壓力計以求結構物整體受力分佈；以投影法（Projection Method）求解大渦模擬（Large Eddy Simulation）方程式；以流體體積法（Volume of Fluid, VOF），描述表面碎波行為。 模式中為能夠適切模擬季風以至於颱風之波浪特性，以頻散關係式為基礎設計之內造波機模組（Internal Wave Maker Module）可依據自氣象局取得的單一波浪波譜觀測資料生成JONSWAP理論頻譜，並以此做為輸入條件產生更符合實際海況的亂數波浪。研究中考量波浪與海流之加總效應，比較相同示性波高條件下，規則波與不規則波衝擊結構時其受力分布，以期提供未來離岸風電場建置之參考。 ;In this research, the three-dimensional numerical simulation and analysis for solving the dynamic loads from waves and currents on the offshore wind turbines is performed. Scenarios focused on the extreme weather conditions. During the typhoon event, the wind-driven storm waves and currents have to be considered while solving the dynamic load on the structures. The Splash3D model was adopted to perform the simulation of the interaction between breaking waves and structures. The core of the Splash3D model is the Truchas model which was developed by Los Alamos National Laboratory (LANL) and featured as high accuracy. Splash3D is capable of solving the dynamic process for the interaction between the structure and fluids with complex breaking free-surface. In order to adequately simulate the waves under monsoon or typhoon, a new wave generation module based on the dispersion relationship is developed. This wave-maker module was used to generate regular waves, irregular waves, and breaking waves under the extreme weather condition. The module was used to simulate the synthetic effect under the effects of waves and currents for obtaining the force distribution on the foundation of the offshore wind turbine.
