眾多的海洋能源中，潮流能源為最適合台灣開發的海洋能源之一，而一般用於水力發電的垂直軸阻力型渦輪機的轉速與機械效率皆偏低，已有許多研究在河道水力發電渦輪機前加裝固定式阻流板，降低水流沖擊渦輪機葉片的凸面所造成的阻力，以提升渦輪機的轉速與機械效益。
因潮流流向會隨著潮進潮退剛好方向相反，也會隨著季節而改變，在渦輪機裝上固定式的阻流板的情況下，當潮流流向改變，潮流可能只衝擊到阻流板而沒衝擊到渦輪葉片，這會造成海潮流渦輪機在擷取能源上的一個阻礙。
因此，本研究設計一款能夠隨潮流方向改變而轉向的阻流板，其原理為在阻流板上加裝導流尾翼，當潮流方向變動時靠著水流衝擊導流尾翼，使阻流板被動旋轉，且阻流板能夠隨著海流方向變動而轉向，不管潮流方向從何而來，渦輪機旋轉的方向固定，才能提升渦輪機的機械功率。因此本論文透過商用分析軟體ANSYS中的Fluent模擬渦輪機與阻流板的轉動情況，並計算渦輪機產生的功率與扭矩；最後，透過成功大學水工試驗所提供的實測結果驗證模擬結果的可信度。
模擬結果顯示導流尾翼裝在阻流板上端時，能夠使阻流板穩定地轉動；而導流尾翼裝在阻流板側邊時，能使阻流板轉動較快，但阻流板無法穩定於水流方向；阻流板的上端和側邊同時裝上導流尾翼，阻流板還是無法穩定地隨著水流方向被動旋轉，根據模擬結果顯示導流尾翼裝在阻流板上端為較理想的設計。

In this study, a deflector that can passively rotate was designed 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 deflector was simulated with commercially available Fluent finite element analysis software and calculated the power and torque generated by the turbine. Finally, the accuracy of the simulation results was verified through experiments.
The simulation results show that the deflector can rotate stably when a simulation diversion tail is added to the top of the deflector. When the diversion tail was added to the side of a deflector, the deflector could rotate faster but the rotational speed was not stable. Therefore, based on the simulation results, the best design would be where the diversion tail is placed on the top of the deflector.

[1]吳文騰, "台灣的能源概況," 科學發展月刊, Vol. 457, pp. 123-126, 2011.
[2]"再生能源科技重要結論," 行政院 2007年產業科技策略會議文集, 2007.
[3]Yi-An Chen, Stability analysis and dynamic simulation of submerged Kuroshio generator system, Master Thesis, Department of Systems Engineering and Naval Architecture College of Engineering, National Taiwan Ocean University, Taiwan, 2014.
[4]Bang-Fuh Chen and Cheng-wei Huang, "Nozzle and Diffuser in Drifting Horizontal Turbine Flow," Proceedings of the Twenty-sixth (2016) International Ocean and Polar Engineering Conference, Rhodes, Greece, 2016.
[5]Yang-Yih Chen, Hung-Chu Hsu and Chao-Wei Su, "Field Test of KW Kuroshio Power-energy Pilot Fauilities in The Open Sea," Proceedings of the 37th Ocean Engineering Conference, National Chung Hsing University, Taiwan, 2015.
[6]Kailash Golecha, T.I. Eldho and S.V. Prabhu, "Influence of the deflector plate on the performance of modified Savonius water turbine," Applied Energy, Vol. 88, pp. 3207–3217, 2011.
[7]Yi-Jia Xin, Numerical modeling studies in the East China Sea and its vicinity, Master Thesis, Department of Earth Sciences, National Taiwan Normal University, Taiwan, 2003.
[8]E. Hau, Wind Turbines: Fundamentals, Technologies, Application, Economics, 2 nd edition, Translated by Horst von Renouard, Springer, 2005.
[9]M. R. Patel, Wind and Solar Power Systems, CRC Press LLC, 1999.
[10]Emeel Kerikous and Dominique Thѐveninand, "Optimal shape of thick blades for a hydraulic Savonius turbine," Renewable Energy, Vol. 134, pp. 629–638, 2019.
[11]Daegyoum Kim and Morteza Gharib, "Efficiency improvement of straight-bladed vertical-axis wind turbines with an upstream deflector," Journal of Wind Engineering and Industrial Aerodynamics, Vol. 115, pp. 48–52, 2013.
[12]Golecha Kailash, T. I. Eldho and S. V. Prabhu, “Performance Study of Modified Savonius Water Turbine with Two Deflector Plates,” International Journal of Rotating Machinery, Vol. 2012, Article ID 679247.
[13]Burçin Deda Altan, Mehmet Atılgan and Aydoǧan Özdamar, “An experimental study on improvement of a Savonius rotor performance with curtaining,” Experimental Thermal and Fluid Science, Vol. 32, pp. 1673–1678, 2008.
[14]Burçin Deda Altan and Mehmet Atılgan, “The use of a curtain design to increase the performance level of a Savonius wind rotors,” Renewable Energy, Vol. 35, pp. 821–829, 2010.
[15]A.H. Elbatran, Yasser M. Ahmed and Ahmed S. Shehata, "Performance study of ducted nozzle Savonius water turbine, comparison with conventional Savonius turbine," Energy, Vol. 134, pp.566-584, 2017.
[16]Mohamed M.H., Janiga G., Pap E. and Thévenin D., "Optimization of Savonius turbines using an obstacle shielding the returning blade", Renewable Energy, Vol. 35, pp. 2618-2626, 2010.
[17]W.-H. Chen, 綠色能源與永續發展(二版). 高立圖書, 2015.
[18]Jia-Wei Liu, Structural Design and Analysis of a Tidal Current Power Generation Turbine, Master Thesis, Department of Mechanical Engineering, National Cheng Kung University, Tainan, Taiwan, 2018.
[19]F. d. O. Antonio, "Wave energy utilization: A review of the technologies," Renewable and sustainable energy reviews, Vol. 14, No. 3, pp. 899-918, 2010.
[20]A. d. O. Falcão, "The shoreline OWC wave power plant at the Azores," Fourth European Wave Energy Conference, pp. 4-6, 2000.
[21]Rafael Waters et al., "Experimental results from sea trials of an offshore wave energy system," Applied Physics Letters, Vol. 90, No. 3, p. 034105, 2007.
[22]L. A. Vega, "Ocean thermal energy conversion primer," Marine Technology Society Journal, Vol. 36, No. 4, pp. 25-35, 2002.
[23]Y. L. Young, M. R. Motley and R. W. Yeung, "Three-dimensional numerical modeling of the transient fluid-structural interaction response of tidal turbines," Journal of Offshore Mechanics and Arctic Engineering, Vol. 132, No. 1, p. 011101, 2010.
[24]Sørensen J. N., Shen W. Z., Munduate X., “Analysis of wake states by a full-field actuator disc model”, Wind Energy, Vol. 1, No. 2, pp. 73-88, 1998.
[25]J. V. Akwa, H. A. Vielmo and A. P. Petry, "A review on the performance of Savonius wind turbines," Renewable and sustainable energy reviews, Vol. 16, No. 5, pp. 3054-3064, 2012.
[26]Y.-C. Li, "The Performance Comparisons of the Lift-type and Drag-type Wind Turbines," NCTU, 2013.
[27]J. F. Manwell, J. G. McGowan and A. L. Rogers, Wind energy explained: theory, design and application. John Wiley & Sons, 2010.
[28]T. V. Nguyen, "A vortex model of the Darrieus turbine," Texas Tech University, 1978.
[29]M. Islam, D. S.-K. Ting and A. Fartaj, "Aerodynamic models for Darrieus-type straight-bladed vertical axis wind turbines," Renewable and Sustainable Energy Reviews, Vol. 12, No. 4, pp. 1087-1109, 2008.
[30]S. Lain and C. Osorio, "Simulation and evaluation of a straight-bladed Darrieus-type cross flow marine turbine," 2010.
[31]Howell R. Qin N., Edwards J. and Durrani N., “Wind tunnel and numerical study of a small vertical axis wind turbine”, Renewable Energy, Vol 35, No 2, pp. 412-422, 2010.
[32]謝曉星，計算流體力學及熱傳學，高立圖書有限公司，1993。
[33]ANSYS, ANSYS FLUENT User’s Guide, ANSYS, Ins., 2011.
[34]K.A. Hafeza, O.A. Elsamni and K.Y. Zakaria, “Numerical investigation of thefully developed turbulent flowover a moving wavy wall using k-ɛ turbulence model”, Alexandria Engineering Journal, Vol 50, pp. 145-162, 2011.
[35]胡坤、胡婷婷、馬海峰，ANSYS CFD 入門指南 計算流體力學基礎及應用，機械工業出版社，2018。
[36]Tzu-Hsiang Lin, Qualitative Analysis of the Performance of a Vertical-Axis Wind Turbine, Master Thesis, Department of Mechanical Engineering, National Chiao Tung University, Hsinchu, Taiwan, 2011.