本研究共分為兩個部分，第一部分探討NREL Phase VI風力機所受之風力負載，透過實驗資料與模擬值之比較，發現因為葉片旋轉效應的影響，若僅使用二維翼型氣動力參數進行模擬，其值與實驗值差異甚大，本研究使用Snel與Lindenburg兩種不同的三維失速延遲修正模型，將旋轉效應造成的影響考慮進去，結果顯示經過修正後的模擬值與實驗值之差距降低，接著探討在不同的節距角與轉速之下，對風力機負載所造成之影響，結果顯示節距角與轉速提高，會使低轉速軸扭矩值提高，其主因為攻角遠離了失速範圍。 第二部份針對NREL 5MW OWT風力機塔架進行應力分析，選擇IEC 61400-3中屬於需分析極限負載的六種設計工況，並配合台灣西部沿岸之海洋參數進行模擬，最後將轉換後的負載輸入至ANSYS Workbench，結果顯示在DLC 1.6b、6.3b的狀況下，塔架之安全係數已低於IEC 61400-3規範建議值，這表示NREL 5MW OWT之原始設計可能不適用於台灣西部沿岸之極端風況與海況，因此本研究繼續探討將原塔架模型作修改，使安全係數高於規範建議值。 ;This study consists of two parts. In part one, we investigated the wind-induced loads on the NREL Phase VI wind turbine. We noticed that if the inputs of simulations were the 2D airfoil aerodynamics coefficients only, the results will be apparently different from the experimental results due to rotating effect of blades. So, we used two different 3D stall delay correction models, which were derived by Snel and Lindenburg, to account for the rotating effect of blades. After modification of aerodynamics coefficients, the results showed well agreement between experiment and simulation. Furthermore, we discussed the wind-induced loads under different pitch angles or rotor speeds. The results showed that raising pitch angle or rotor speed increased the Low Speed Shaft Torque due to A.O.A was far from stall range. In part two, the stresses of NREL 5MW OWT tower were investigated. We studied six design load cases (DLCs) which should be processed ultimate load analysis according to the IEC 61400-3 standard. The ocean parameters of Taiwan west coast were adopted as the inputs of DLCs. The output loads of GH-Bladed software were transformed and imported to ANSYS Workbench. The results showed that the safety factors of tower under DLC 1.6b and 6.3b was lower than those recommended in IEC 61400-3. It indicated that the original design of NREL 5MW OWT may not afford the extreme wind and ocean conditions at Taiwan west coast. Therefore, we modified the thickness of tower to make the safety factor of tower higher than the suggestion.
