| 摘要: | 發展離岸風能幾乎已成為國際的趨勢，台灣優勢在於擁有許多優良離岸風場，但台灣颱風與地震頻繁的地理位置特性使得國際規範難以直接轉移。為開發離岸風能的困難與阻礙，本文建立模擬風機在均勻風條件下分析氣動力負載的方法，以商用軟體ANSYS Fluent進行模擬。主要分析的條件參考NREL Phase VI 風洞實驗，條件為0度、3度、6度三種節距角，7 m/s、10 m/s、15 m/s、20 m/s、25 m/s五種風速共十五種條件，與實驗結果比對並探討葉片的氣動力負載，分析項目包括周為流場的流線、壓力係數、正向力系數、切向力系數、升力係數、阻力係數、翼襟彎矩、葉沿彎矩、低速軸扭矩。結果顯示在低風速條件，葉片背風側尚未發生邊界層分離前，模擬足夠準確，但在風速升高使攻角上升的條件下，邊界層分離現象發生，而對於發生邊界層分離的時機以及發生邊界層分離後的行為，模擬結果顯示有誤差。;Development of offshore wind power has almost become a trend. There are many of the best offshore wind farms located in Taiwan. However, Typhoons and earthquakes happened frequently in Taiwan, which obstructs international offshore wind power technology being transferred to Taiwan directly. We used commercial software ANSYS Fluent to build a model to analyze aerodynamic load of wind turbine in uniform flow conditions. Results of the simulation were compared with NREL Phase VI wind tunnel experiments, which include 0°, 3°, 6° three different pitch angles and 7 m/s, 10 m/s, 15 m/s, 20 m/s, 25 m/s five different inlet velocities. The streamline, pressure coefficient, normal force coefficient, tangential force coefficient, lift force coefficient, drag force coefficient, flap bending moment, edge bending moment and low speed shaft torque were investigated. The simulation results are accurate enough at the low wind speed conditions. On the other hand, when the angle of attack increases as the wind speed increase, stall phenomena happen. The results show that simulation is not accurate enough to predict the timing of stall and the flow behavior after the stall occurs. |
