臺灣博碩士論文加值系統

本研究以數值模擬計算探討同軸雙旋翼直升機在懸停時，不同旋翼翼型組合所產生的氣動力性能。旋翼組是由上、下各三片葉片所組成。模擬之旋翼模型依尺寸分有小旋翼組與大旋翼組。
小旋翼組部分，組合翼型的葉片翼切形有對稱之NACA0012與非對稱之Viper-X兩大翼型，其中Viper-X又在旋翼的葉尖分成為後掠角0、20與35度這三種翼型。大旋翼組使用了Viper-X翼切形後掠角20與35度兩種，並對其旋翼葉尖再加入10、20與30度的上反角與下反角。
本研究中，使用了ANSYS公司的CFX商用軟體，來進行流場域的模型與網格建構；使用Fluent軟體來進行數值模擬計算，得到流場細部解如升力、扭矩等數值，以評估各式翼型組合。研究結果顯示，對小旋翼組而言，上旋翼為Viper-X葉尖後掠角35度、下旋翼為Viper-X葉尖後掠角20度之組合結果為最佳。大旋翼組中，加入葉尖上反角所得結過不理想，而葉尖下反角的設計以Viper-X葉尖後掠角20度、下反角10度的翼型為較佳設計。

In this study, coaxial rotors with various blade combinations was simulated numerically to study the aerodynamic performance during the hovering. The upper and lower rotors each are composed of three blades. In terms of dimension, two coaxial rotors, small and large, are considered.
For the combination of the small rotor, the blade of the symmetrical airfoil NACA0012 and the asymmetrical airfoil Viper-X are used. While on the blades tip of Viper-X, three sweepback angles, 0, 20 and 35 deg, are applied. For the simulation of large rotor, two sweepback angles of blade-tips, 20 and 35 deg, and dihedral/anhedral angles of 10, 20 and 30 deg are taken into account on the blades of Viper-X airfoil.
In this study, the commercial software of ANSYS-CFX is used to construct grid on the flow field. The Fluent software is used to carry out the numerical simulation for obtaining the data of detailed flow field, lift and torsion, and then evaluation of rotor blade combinations. For the small rotor, the upper rotor of the Viper-X blade of 35 deg tip sweepback combining with the lower rotor of the Viper-X blade of 20 deg tip sweepback is the best in the cases studied. As for the case of large rotor, the results show that the tip dihedral design is not satisfactory. On the contrary, the design of the Viper-X blade of 20 deg tip sweepback and 10 deg anhedral is relatively a better design, among the rotor combinations in the present simulation.

誌謝 I
摘要 II
ABSTRACT III
目錄 V
表目錄 VII
圖目錄 IX
符號說明 XIV
第一章 緒論 1
1.1前言 1
1.2文獻回顧 3
1.3 研究目的 6
第二章 物理模型與計算方程式 8
2.1物理模型 8
2.2統御方程式 9
2.3紊流計算模型 10
第三章 數值方法 27
3.1模擬程序 27
3.2離散方法 30
3.3邊界條件與計算條件 31
3.4收斂準則與鬆弛因子 31
第四章 結果與討論 43
4.1結果驗證 43
4.2小旋翼組的結果與討論 43
4.3大旋翼組的結果與討論 50
第五章 總結 89
5.1總結 89
5.2未來展望 91
參考文獻 96
附錄 98

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