本研究為探討兩種不同幾何外型的水平軸風力發電機葉片之空氣動力性能差異，一種是利用葉片元素動量理論所設計之葉片，另一種是平均弦長無扭矩角之葉片（基準葉片）。主要是探討由葉片元素動量理論設計之葉片為什麼相對於基準葉片，有較好的功率係數。
因此將探討空氣動力特性在葉片上對效率之影響。利用風洞實驗量測兩種葉片的功率係數以提供實驗數據給數值模擬驗證其模擬值；在數值模擬方面，首先利用二維模擬找出最適合的y^+值，並應用於三維模擬找出最適合的紊流模型；因此，在數值模擬計算中利用二階上風離散法之Shear-Stress Transport (SST) k-ω紊流模型結合SIMPLE數值方法去求解穩態Reynolds-averaged Navier Stokes方程式以得到葉片的空氣動力性能；利用數值模擬觀察葉片表面之流場現象以解釋其空氣動力性能之差異。
由葉片流場觀察中，可以發現葉片元素動量理論設計之葉片其根部扭矩角會減少分離流的發生，在風速10m/s翼尖速度比5.236時，由於非常接近設計翼尖速度比，因此葉片吸入側的流場幾乎沒有發生分離現象，所以相對基準葉片有較高的功率係數。

The purpose of this study is to investigate the differences of the aerodynamic performance on the horizontal-axis wind turbine blades of two different type of geometry shape. One of the blade is designed by blade element momentum theory (BEMT), and the other blade is a non-twisted with a constant chord length, which is called Baseline blade. In order to investigate on the BEMT designed blade, in which has a great performance of power coefficient than Baseline blade. Therefore, the effect of the aerodynamic performance on the blades would be investigated in this study.
It would use the wind tunnel experiment to measure the power coefficients of these two blades for the numerical simulation to verify the experimental data. In the numerical simulation, the appropriate y^+ value is found by 2D simulation and the value would apply in 3D simulation in order to find the appropriate turbulence model. In addition, the aerodynamic performances of the blades are obtained by using the SST k-ω turbulence models of 2^nd upwind scheme with SIMPLE algorithm method to solve the Reynolds-averaged Navier Stokes (RANS) equations. It would observe the flow fields phenomenon on blade surface for explaining the differences of the aerodynamic performance by using the numerical simulation.
From observing the flow fields on the blades, it can be seen that the BEMT designed blade would reduce the separated flow occurrence at the root due to the twist angle of the blade. At the wind speed of 10 m/s with the tip speed ratio of 5.236 which is very close to the design tip speed ratio of 5, the BEMT designed blade has a greater power coefficient than Baseline blade, because the flow field on the suction side of the blade is not occurred the separation.

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