本研究透過計算流體力學(CFD)模型進行NACA0015翼剖面的垂直軸風機葉片性能研究. 透過商用套裝軟體ANSYS Fluent來進行模擬. 選擇壓力耦合方程組的半隱式(SIMPLE)方法演算法來求解不可壓縮納維爾-史托克(Navier-Stokes)方程式. 紊流模型模擬選擇k-ω SST(剪應力傳輸)紊流模型. 使用攻角0°到40°升力和阻力係數的模擬結果進行與實驗的驗證比對, 用以確認邊界層的分布狀況.並進行網格數與時間步的檢查,以確認該模擬的精準度. 為了觀察三維(3D)的效果, 另外發展出一個二維半(2.5D)模型, 並與二維(2D)模型進行比較. 最後, 從翼突節設計的葉片比較直線翼葉片的方式來獲得推力的預測. 總而言之, 使用翼前緣突節葉片垂直軸風機的推力會比直線翼風機的推力更低, 而使用翼後緣突節葉片垂直軸風機的推力會比直線翼風機的推力更高. 隨著風機翼前緣波狀葉片的振幅的增加和波長的降低, 推力值會下降, 而隨著風機翼後緣波狀葉片的振幅和波長的增加, 推力值會上升. 主要由於在風機葉片的突節區域產生的渦流結構所影響.

The performances of a VAWT blade with NACA0015 airfoil section were investigated through the CFD model. The simulations were carried out by the commercial software ANSYS FluentTM. The Semi Implicit Method for Pressure Linked Equations (SIMPLE) algorithm are chosen to solve the solutions of the incompressible Navier-Stokes equations. The k-ω SST (shear stress transport) turbulence model was selected for the turbulence flow simulations. The grid numbers and time step sizes were then examined to confirm the simulation accuracy. To exam the 3D effect, a 2.5D model was additionally developed and compared with 2D model. Finally, the predictions of thrust obtained from the blade with tubercle design were compared with the ones from the straight blade. Overall, the thrusts of VAWT with tubercle leading edge turbine blades were lower than the ones with straight blade, and the thrusts of VAWT with the tubercle trailing edge turbine blades were bigger than the ones with straight blade. The values of the thrust decreased with increasing amplitudes and decreasing wavelengths for the leading edge wavy blade, and the values of thrust increased with increasing amplitudes and wavelengths for the trailing edge wavy blade. We found out that these conditions are due to the structure of the vortices generated at the tubercle region of the turbine blade.

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