液靜壓軸承由於其高承載力，高剛性，高阻尼和高精度的特性而被廣泛應用於大型，高精度的工具機上。本文提出了一種反蓮花結構，並將其應用於液靜壓軸承的封油面上，以提高其性能。這種特殊結構的表面具有良好的疏液性，且可以產生表面滑移現象。
根據建立的反蓮花模型，為了在表面結構上產生一個適當的滑移邊界條件，優化了相關的設計參數。通過改變軸承封油面上功能性表面的孔洞直徑，深度和排布可以優化封油面上的壓力分佈，從而起到提升軸承性能的目的。此外反蓮花結構與蓮花結構做了比較。
根據理論模型，功能性表面上的孔洞直徑在幾十到幾百奈米，陽極氧化鋁技術能夠在純鋁的表面製造出符合要求尺寸的孔洞。在陽極氧化鋁的表面進行表面改性後就製造出了反蓮花結構。該種結構的表面水滴接觸角能夠達到150°左右，具有超疏水的能力。通過微粒子影像測速法（μ-PIV）測量了其表面的速度滑移情況。此外，通過耐磨實驗，顯示其有較好的耐磨性。

Hydrostatic bearings (HSBs) featuring high load-carrying capacity, high stiffness, high damping, and high accuracy are widely used in large-size precision machine tools. This study presents a functional negative lotus surface structure fabricated underneath the bearing land for enhancing the performance of HSBs. The structure demonstrated a property of lyophobicity, which led to a slip boundary condition.
A theoretical model of the negative lotus structure was first constructed. Then, based on the model, the design parameters were optimized to generate a required slip boundary condition on the surface of the proposed negative lotus structure. As an example, varying the discrepant density as well as the diameter and depth of the nanoholes optimized the pressure distribution beneath the land. The performance enhancement of the HSB under a high liquid pressure was validated by calculating the load-carrying capacity, initial stiffness, and energy consumption. Existing lotus structures and the proposed negative lotus structure were compared.
According to the theoretical model, the hole diameter was evaluated and the anodic aluminum oxide (AAO) technique was used to fabricate samples. The water contact angle on the negative lotus structure reached approximately 150°. The results of micro particle image velocimetry experiment showed significant slip lengths of the negative lotus structure in liquid. In addition, the test result of abrasive resistance revealed that the proposed negative lotus structure demonstrated superior wear resistance to the existing lotus structures.

Abstract ii
摘要 iv
Acknowledgements v
Table of Contents vi
List of Tables viii
List of Figures ix
List of Symbols xi
Chapter 1 Introduction 1
1-1 Background 1
1-2 Literature Review 3
1-2-1 Performance Enhancements of HSBs 3
1-2-2 Functional Surface Structures 5
1-3 Contents of this Study 8
Chapter 2 Theoretical Analyses 9
2-1 Basic Formulations of Lyophobicity 9
2-2 Functional Surface Structures Design 12
2-2-1 Lotus Structure Design 12
2-2-2 Negative Lotus Structure Design 15
2-3 Fundamental Theories of HSBs 18
2-3-1 Nonslip Boundary and Slip Boundary 18
2-3-2 Flat Plate Flow Model and Governing Equation 21
2-4 Performance of HSBs with Functional Surfaces 25
2-5 Optimization of Pressure Distribution for HSBs 27
Chapter 3 Experimental Studies 31
3-1 Preparation of Functional Surfaces 31
3-2 Mechanical Durability Tests 33
3-3 CA Measurements 35
3-4 Measurements of Slip Lengths on the Functional Surfaces 35
3-4-1 Microchannel Design and Fabrication 35
3-4-2 Micro particle Image Velocimetry Measurement 40
Chapter 4 Results and Discussion 47
4-1 Performance of HSBs with Functional Surface Structures 47
4-2 Simulation Results of Drag Reduction Performance 51
4-3 Experimental Results 56
4-3-1 Abrasive Resistance Tests 56
4-3-2 Contact Angles of Functional Surfaces 57
4-4-3 Slip Lengths on the Functional Surfaces 60
Chapter 5 Conclusions and Future Works 61
5-1 Conclusions 61
5-2 Future Works 62
References 64
Appendix A 68

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