能源為目前最重要的議題之一，風力發電更是我國重要的綠能發電之一。風力機朝著大型化與發電容量更大的機型發展，伴隨而來的就是結構負載提升及運轉成本增加。 本研究針對2.0 MW大型風力機使用ANSYS Fluent軟體進行風況入力分析。先進行流場設定條件檢測及葉片模型節距角0°位置檢測。然後探討在正常發電及極限風速下的風力機受力狀況，並討論風切、紊流強度及轉向錯位等因素之影響，再使用ANSYS Workbench 15.0軟體，將流場分析的結果導入進行穩態、暫態應力分析和模態分析，觀察塔架應力分布情形，並取得各法蘭處截面之應力，進而得到螺栓最大應力。 研究結果顯示，可將葉片在迎風面產生最大投影面積時之位置設定為節距角0，並由風力機實際操作狀況得到驗證。紊流強度變大時，會增加風力機的總正向入力，且平均風速愈高時之增加程度愈大。轉向錯位對於側向入力的影響很大，在極限風速且風力機靜止(颱風)狀況下，轉向錯位在67.5時產生最大側向入力。應力分析方面，在正常操作情況下或IEC 61400-1規範中所要求的特定風速下，均不會造成風力機塔架的損壞。模態分析上，在正常發電額定轉速下並不會對塔架造成共振效應。螺栓應力分析方面，在螺紋根部有很大的集中應力，會造成局部的塑性變形，且螺栓截面應力與經驗公式所計算之值相符合。 ;Energy issue is one of the most important topics in Taiwan, and so is the wind power. The size of wind turbine is getting larger to satisfy the needs of electric energy, but it results in an increment of cost and external loads. The wind-induced loads and stresses of Vestas V80-2MW wind turbine were analyzed. The author inspected the setting of inflow conditions first, and then investigated the wind-induced loads of the wind turbine under both normal power production and several extreme wind speeds. The influence of wind shear, turbulence intensity, and yaw misalignment were discussed. The results showed that the pitch angle of blade was at 0 position when the projected area of a blade was maximum. The wind-induced loads increased with turbulence intensity, and such increment of loads increased with mean wind speed. The yaw misalignment had an apparent effect on the lateral force acting on the tower. When the wind turbine was under extreme wind speed and parked, e.g., typhoon, the maximum lateral force occurred at 67.5 of yaw misalignment. With respect to the stress analysis of tower, the tower of wind turbine will not fail under normal power production or the specific wind speeds that were required in IEC 61400-1 standard. In modal analysis, the resonance of tower will not occur under normal power production with rated rotor speed. In stress analysis of bolt, the stress at bolt root was very high due to the effect of stress concentration, which resulted in local plastic deformation. The stress at the center of cross-section of bolt was identical to the value that was calculated by empirical formula.
