本次研究範疇運用於小型噴射引擎飛機，透過計算流體力學模型(CFD)進行NACA0021機翼經突節方式設計後之性能研究。利用商用套裝軟體SolidWorks及Workbench設計機翼並使用ANSYS Fluent來進行模擬。長期以來，地面的風洞實驗是測量飛機氣動力數據和試驗新的氣動力現象以及流體概念的主要方式，藉由反覆的設計和實驗，並借助經驗的判斷確定最終的設計方案，因此對歷次經驗的依賴性較強，相對的，設計的週期較長、費用亦較高。氣流通過機翼表面時，會分流成數道氣流，因環境條件不同產生層流或紊流，層流為穩定氣流之表徵，紊流則出現在速度變動的地方，這種波動導致流體介質之間相互交換動量、能量及空氣黏滯力變化，而且引起物理數量上的波動。隨著計算工作站電腦和數值模擬軟體技術的發展，數值模擬開始廣泛應用於機翼設計和流場分析中，近幾十年來的研究已顯示其特有的能力和潛力。為求研究便利性，使用模擬方法進行運算，選擇壓力耦合方程式的半隱式演算法來求解不可壓縮納維爾-史托克(Navier-Stokes equation)方程式。
進行軟體操作時，設定翼前緣突節為變數因子，突節紊流模型模擬選擇SST k-ω(剪應力傳輸)紊流模型，並進行不同振幅之突節機翼的數值模擬，再擇由其中表現最優異之翼形進行不同機翼攻角分析，獲得升力和阻力係數的模擬結果並與實驗的驗證相對照，以上設定透過文獻閱讀以確認邊界層的分布狀況。接著，翼突節設計的機翼以相同於直線翼的驗證方式及邊界條件來獲得各項升、阻力係數預測。先透過套裝軟體SolidWorks及Workbench繪製機翼輪廓並建立網格，再利用所學的空氣動力學、流體力學觀念運用於模擬軟體進行運算，最後將結果陳列比較並分析數據。
翼突節機翼設計概念始於海洋生物座頭鯨的靈感，也就是所謂的仿生學，生物仿生我們首先要了解的內容為地球經過38億年進化，產生的自然世界到處都是充滿新奇創意的生命形式、系統和過程，它們都經過了時間的考驗，環境的汰弱，具有持續生存發展的能力，可以供人類模仿借鑒。生物仿生從這些自然原則中吸取靈感，用於解決人類社會面臨的問題，以上思維可以支持業界將翼突節機翼的設計運用於目前航空界。透過來自於海洋生物座頭鯨的靈感，身上突節構造的胸鰭和大小相等的平滑胸鰭比較起來，座頭鯨胸鰭的隆起前緣能增加百分之八的升力、減少高達百分之三十二的阻力，原理為突節構造似渦流製造機，旋轉的渦流將動量注入水流，讓水流吸附在鰭的上層表面，而不是分叉到上下兩側。這個效應可延緩攻角較陡時引發的失速現象，此外，和流線形的胸鰭比較起來，座頭鯨巨大扇貝形的胸鰭在切入急流時的角度可大幅增加攻角，不致失控。
將仿生學運用在航空領域，從模擬機翼在固定雷諾數下的流場分析結果得知，使用翼前緣突節機翼的升力係數會比直線翼機翼的升力係數高，而未採用翼突節設計的機翼的升力係數會比直線翼機翼的升力係數低；使用翼前緣突節機翼的阻力係數會比直線翼機翼的阻力係數低，而未採用翼突節設計的機翼的阻力係數會比直線翼機翼的阻力係數高。本研究機翼採用NACA0021來進行數值模擬與性能分析，利用NACA0021機翼為範本設計突節結構，選擇使用商用CFD套裝軟體ANSYS Fluent進行計算模擬分析與觀察機翼流場現象，模擬內容包含直線翼機翼與翼突節設計之研究比較，壓力梯度法採納格林-高斯基於節點法(Green-Gauss Node Base)處理直線機翼及各突節機翼較複雜幾何之結構型網格計算。內插法及時間項皆採用二階上風法(Second Order Upwind)，以減少機翼複雜流場計算迭代誤差及修正數值擴散。

The study of the airfoils with tubercles based on NACA0021 was simulated through the commercial software ANSYS Fluent. By progressing three types of designed airfoils to compare to the ordinary one, getting obvious to realize the variation of life coefficient and drag coefficient of them. The Semi Implicit Method for Pressure Linked Equation (SIMPLE) method was subsequently chosen to take care of the solutions. There are several turbulence models in CFD aspect nowadays, the SST k-ω turbulence model was considered to be more suitable for this case. By the way, in order to exam the 3D effect, the relevant 3D model and domain was schemed and compared with the other models. The experiments and simulations were meaningful for its own purpose respectively. In terms of the time efficiency, later was chosen to conduct the case which was emulating the real situation when people fly. Finally, the predictions of life coefficient and drag coefficient were all obtained from the airfoils with tubercles design based on the straight airfoil. According to the statistics and Computational Fluid Dynamics (CFD), the lift coefficient of airfoil with tubercles design was lower than straight airfoil, and the drag coefficient of airfoil with tubercles design was also lower than comparison. After carrying out the simulation, the value of the lift and drag coefficient diminished with increasing amplitude on the leading edge. Hence, we found these types of airfoils with tubercles on the leading edge were feasible for making a significant improvement in lift and drag coefficient of NACA0021.

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