在過去的幾十年來，人們一直進行火星上空氣動力學的研究，以了解和開發適合火星的最佳飛行器。本研究主要為討論在厚度改變的情形下，三角翼型在火星大氣條件下的空氣動力性能，採用有限體積法求解0° 至 16° 攻角下，高低流速的數值研究，低雷諾數 Re範圍在 3000 ~ 7000 之間為層流區域，較高雷諾數 Re範圍 80000~120000為過渡流區域。本研究討論改變翼型的最大厚度，以了解翼型在各種流動條件下的空氣動力效率。根據研究結果顯示在幾個攻角下，存在著不穩定的升力係數，論文中呈現壓力、速度等值線和流線圖。並且提供了翼型的表面壓力係數，以了解壓力分佈。當流體分離氣泡開始接近吸力表面的頂點時，升力係數Cl 產生非線性行為。除了分離氣泡之外，對於低與高雷諾數Re分別在攻角α = 16°及α = 14°、16°形成迴流再循環區。在低與高雷諾數Re的分別於攻角 α = 7° 和 α = 2° 處得到最佳的結果。

Research on Mars aerodynamics has been done for the last few decades to under-stand and develop optimum aerial vehicles for Mars. The present research aims to understand the aerodynamic performance of a triangular airfoil in Mars atmospheric conditions having a variable thickness. A numerical investigation using a Finite Volume Solver has been performed for 0° to 16° angles of attack at low and high flow velocities. For low flow velocities Re. ranging between 3000 ~ 7000, and for the speeds near laminar to turbulence transition, Re. 80000~120000 has been considered. The airfoil's maximum thickness has been varied to understand the aerodynamic efficiency of the airfoil in various flow conditions. The results have shown an unsteady lift coefficient at a few angles of attack. Pressure, velocity contours, and streamlines have been reported. The pressure coefficient on the airfoil surface has also been presented to understand the pressure distribution. The nonlinearity in Cl appears as the separation bubble begins to approach the apex on the suction surface. Apart from the separation bubble, a flow recirculation zone is generated for low and high Re. at α = 16°, and α = 14°, 16° respectively. The highest aerodynamic performance for low and high Re. is at α = 7° and α = 2° respectively.

Chinese Abstract……………………………………………………………………………………………………………………………i
English Abstract……………………………………………………………………………………………………………………………ii
Acknowledgements or Preface………………………………………………………………………………………………iii
Table of Contents…………………………………………………………………………………………………………………………iv
List of Tables…………………………………………………………………………………………………………………………………v
List of Figures………………………………………………………………………………………………………………………………vi
Symbols……………………………………………………………………………………………………………………………………………………xii
Chapter 1 Introduction………………………………………………………………………………………………………1
1.1 Research Motivation……………………………………………………………………………………3
1.2 Research Objective………………………………………………………………………………………5
Chapter 2 Literature Review…………………………………………………………………………………………7
Chapter 3 Research Methodology…………………………………………………………………………………9
3.1 Governing Equations……………………………………………………………………………………9
3.1.1 Turbulence Models…………………………………………………………………………………………9
3.1.2 Knudsen Number…………………………………………………………………………………………………15
3.2 Solver and Software……………………………………………………………………………………16
3.3 Convergence Criteria and Simulation Type……………………………17
3.4 Mars Atmospheric Conditions………………………………………………………………20
3.5 Boundary Conditions……………………………………………………………………………………21
3.6 Computational Domain and Meshing…………………………………………………22
3.7 Grid Independence Study…………………………………………………………………………24
3.8 Code Validation………………………………………………………………………………………………25
Chapter 4 Results and Discussion……………………………………………………………………………26
4.1 Low Reynolds Number Flow………………………………………………………………………26
4.2 High Reynolds Number Flow……………………………………………………………………36
4.3 Aerodynamic Performance…………………………………………………………………………47
Chapter 5 Conclusion……………………………………………………………………………………………………………49
Reference………………………………………………………………………………………………………………………………………………51
Appendix I……………………………………………………………………………………………………………………………………………54
Extended Abstract…………………………………………………………………………………………………………………………182
Curriculum Vitae……………………………………………………………………………………………………………………………191

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