有鑑於再生能源的需求日益增加，對於四面環海的台灣，海浪或潮流發電是十分適合開發的海洋能源，用於水力發電的垂直軸阻力型渦輪機其啟動轉速低及產生高扭力的特性，十分適合潮流發電，但潮流偏低的速度造成發電效率低讓其發展受限，許多研究已說明在垂直軸阻力型渦輪機前加裝固定式阻流板，透過降低水流直接衝擊渦輪機葉片的凸面造成的阻力負扭矩，以提高渦輪機的轉速，進而使渦輪機發電效率提高。
然而，潮流流向是會受到季節及漲潮退潮等因素而有所改變，故若渦輪機只加裝固定式的阻流板，當潮流流向發生改變時，阻流板則無法有效的提高渦輪機的效率。
因此，本研究透過在阻流板上加裝導流尾翼的設計，使整體阻流板能在任何水流方向下，皆能透過水流衝擊導流尾翼而被動轉向，有效的提高渦輪機的效率。而本研究目的在於針對此阻流板及導流尾翼的設計做探討，使阻流板及渦輪機能更快速穩定並達到最佳的發電效率表現，設計參數包含阻流板的縮減角度、阻流板與渦輪機的間隙及導流尾翼的高度。透過商業分析軟體ANSYS-CFX模擬計算渦輪機與阻流板的轉動情況及流場變化，同時與成功大學水工試驗所提供的實測結果做驗證，並探討加裝最佳化阻流板的渦輪機其性能表現。
模擬結果顯示在加裝最佳化阻流板後，渦輪機在TSR為0.57時，最大Cp值為0.306，與未加裝阻流板的渦輪機相比，最大Cp值相差3.13倍，而相較於加裝原始設計阻流板的渦輪機，最大Cp值則提升了18%。

In the present study, a deflector that can passively rotate is proposed for a tidal current power generation turbine, where when the flow direction changes, the deflector can rotate with the current direction. The rotation of the turbine and the deflector are simulated with finite element analysis software, and the power and torque generated by the turbine are calculated. In addition, the accuracy of the simulation results is verified through experiments. The purpose of this study is to maximize the output power of a hydrokinetic turbine by optimizing the geometry of the deflector and the diversion tail. The optimized deflector and diversion tail design are considered in the parameters, including the deflector reduction angle, the gap between the deflector and the turbine, and the height of diversion tail.
The optimal geometry performance of the deflector and diversion tail is compared to the turbine without the deflector and with the original deflector over the entire operational range using CFD simulations. Without the deflector, the maximum power coefficient of the turbine was 0.0979 at a tip-speed ratio of 0.4. The maximum power coefficient of the turbine was 0.306 at a tip-speed ratio of 0.57 when using the optimal deflector. The results indicated that the power coefficient of the turbine was 3.13 times greater after adding the optimal deflector compared with the turbine without the deflector, and the power coefficient increased by 18 % compared with the turbine with the original deflector.

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