面對能源危機的衝擊，全世界皆投入大量資金於替代能源之研究與開發，而替代能源中又以風力發電最屬潛力無窮的自然資源。本文利用大尺度渦漩模擬(LES)進行一垂直軸風力發電機之計算流體力學(CFD)數值模擬，首先對雷諾數為1.3×10^5至3.0×10^5、零攻角狀況下的平板進行模擬分析，並以1/7-Power Law解析解作為比對值，其阻力係數結果誤差能夠在20%以內。爾後建立一符合本研究之新型垂直軸風力機之數值模型，經過對平板之表面摩擦及攻角變化之影響進行誤差損失修正，結果發現平板葉片攻角變化來自於測試地點的風場變化，當攻角變化為-5°、風速為10 m/s、風力發電機之周速比為0.125時，輸出功率係數 之誤差修正至21%。最後以建立的數值模型對針對不同的葉片長度比 與不同的入口風速的垂直軸風力機數值模型進行模擬，從結果可以發現葉片長度比為0.8時，有較佳的輸出功率係數，其值在 為0.25時達到0.070。再進行不同風速狀況下的模擬，由風速為3 m/s之結果可知在周速比 為0.25時即擁有0.238的高扭力係數值，說明此新型垂直軸風力機沒有啟動性的問題。吾人便以此模擬方式進行葉片的改善設計，建構更為良好的新型垂直軸風力機。

Establishment of a reliable simulation model to execute the numerical analysis and predict the aerodynamic performance associated with an innovative vertical axis wind turbine (VAWT) is the main goal of this research. This new VAWT owns a 3-dimensional matrix of the wind blade panels which operate in 90 degree oppositional to each other and move uniformly in the same direction as the wind. Because this VAWT’s rotary direction goes with the wind, it creates the smooth revolution of the entire blade-panel matrix and the smooth transfer of wind energy to the vertical shaft.
Also, this integrated study is composed of the CFD calculation with LES scheme and the experimental field test for the performance verification. First of all, a series of low-Reynolds-number numerical simulation, ranging from 1.3×10^5 to 3.0×10^5, on the flow passing a horizontal plate is performed and compared to the 1/7-power-law solution for validating the accuracy of this LES model. Subsequently, after taking into account of the corrections caused by the surface friction and the angle-of-attack variation, this LES simulation outcome is agree well with the experimental data and presents an acceptable 21% deviation on the power coefficient from the field-test measurement under the condition of -5° angle-of-attack, 10 m/s wind speed, and TSR=0.125.
Later, a parametric study on the blade length ratio (β) and the wind velocity (V) is carried out to realize their corresponding influences on this VAWT’s aerodynamic performance. Within all the cases considered here, the best power coefficient (Cp=0.070) appears at β=0.8 for the case of TSR=0.25. Additionally, the highest torque coefficient (Ct=0.238) is found at the case of V=3m/s, TSR=0.25, and β=0.9. The high torque coefficient implies that this new VAWT owns a good starting capability even under a low wind speed. Furthermore, the detailed flow patterns and torque contribution for each blade/panel at various locations are illustrated and analyzed clearly in this work; thus this established model can be applied for the further performance improvement of this VAWT.

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