有鑑於地球環境日益惡化，科學家紛紛開始著手研究較環保的替代能源，風力發電因而開始蓬勃發展。藉由風力驅動葉片來產生電能，除了其乾淨的特點之外，現今的技術發展成熟，已經可以提供大量且穩定的電力。本論文以NREL Phase VI 風力機為原型，做初步的模擬驗證，和實驗值比對亦獲得良好的結果。為了進一步增加風力發電的發電效率，本研究對葉片外型加上翼尖小翼，期盼能減少翼尖產生之誘導阻力，進而提升風力發電的輸出功率。近年來，計算流體力學廣泛應用於工程分析中，故本篇研究亦利用計算流體力學來分析加裝翼尖小翼之水平軸風力機性能，同時，考量到台灣地處季風氣候，炎熱多雨，因此，也針對大雨條件下之風力機性能利用多相流方法進行模擬分析。 As wind turbine continues to grow larger, problems associated with aerodynamics will become more critical. Thus, the wind energy technical research community has begun to seriously consider the aerodynamic control methodology. The power efficiency of a wind turbine is the index to show its capability of power generating. To improve the wind turbine efficiency, some special inventions are created. In recent years, the experience of benefit from the winglet on aircraft makes engineers to put the device on wind turbine blades to improve the efficiency of power generating. Also, today the weather hazards and its impacts have been researched for many years in areas such as aviation. Thus rain effect in this work is investigated and is the main focus of this thesis. The heavy rain condition is validated through large numbers of water particle. How the rain can affect the performance of wind turbine is still a problem. Besides comparison between regular and wingleted turbine blade, we also analyze the performance of wingleted turbine with rain and no-rain conditions through numerical method. Therefore, the present research tries to apply CFD (Computational Fluid Dynamics) technology in order to simulate the behavior of turbine blades with winglet. As the development of CFD commercial code, such like FLUENT, and CFD series, all of these can offer the fully modeling capability and good reliability. In this work FLUENT 6.3.2 is used to simulate flow of three bladed wind turbines, and both the pressure coefficient and torque coefficient are solved. Our results show that about 6 percent performance increase for a wingleted wind turbine and heavy rain situation can also enhance the thrust coefficient of our investigated wind turbine by a few percent. The research finding created here may represent a huge potential power gain if future wind turbine configuration and construction site are properly designed and chosen.
