臺灣博碩士論文加值系統

本文主旨在以分子動力學模擬奈米液滴噴注，透過加壓的方式，使奈米尺度下金原子容器內的水因為壓力的推動，將水分子從噴口擠出而形成液滴噴注的現象。模擬的物理模型採用自然邊界條件，使用F3C水勢能模型來描述水分子的行為，其中包括了鍵長、鍵角、凡得瓦力和庫倫靜電力的勢能函數。最後可以模擬出水分子的噴注行為，並且了解噴口大小、外加力量和模擬溫度如何影響水分子液滴噴注的行為。

This research mainly aims at the simulation of water molecules nanojet droplet formation using molecular dynamics simulation. The water contained in a nano-scale chamber beneath a nozzle opening is heated. Using force to push water molecules out of nozzle. Nanojet of water drop is expected to form in the vicinity of nozzle. The simulated 3D physical model adopted with the natural boundary condition. Water's behavior is described by F3C water potential energy model, which contains bond length, bond angle, Van der Waals and electrostatic potential. Finally the process of the water molecules nanojet can be simulated and it can be seen that how the dimension of nozzle diameter, force and simulated temperature influences the nanojet of water.

中文摘要 i
英文摘要 ii
誌謝 iii
目錄 iv
表目錄 vi
圖目錄 vii
符號說明 x
一、 緒論 1
1.1 研究目的與動機 1
1.2 文獻回顧 2
1.3 本文架構 3
二、 分子動力學原理介紹 4
2.1 勢能函數選擇 4
2.1.1 水分子間作用勢能 4
2.1.2 金原子間作用勢能 5
2.1.3 水分子與金原子間的作用勢能 6
2.2 設定初始條件 9
2.3 運動方程式 11
2.3.1 Gear五階預測修正算法 11
2.3.2 Verlet演算法 13
2.3.3 Leapfrog演算法 14
2.4 週期邊界條件 15
三、 數值模擬方法 17
3.1 截斷勢能（Truncated potential） 17
3.1.1 Verlet List鄰近列表 17
3.1.2 Cell Link鄰近列表 18
3.1.3. Verlet List鄰近列表結合Cell link鄰近列表法 19
3.2 無因次化 21
四、 結果分析與討論 22
4.1 模型驗證 22
4.2 物理模型 27
4.3 噴口大小對於液滴噴注的影響 30
4.3.1 初始條件設定 30
4.3.2 結果分析 30
4.4 推力大小對於液滴噴注的影響 48
4.4.1 初始條件設定 48
4.4.2 結果分析 48
4.5 溫度高低對於液滴噴注的影響 61
4.5.1 初始條件設定 61
4.5.2 結果分析 61
4.6 實驗與模擬之比對 74
五、 總結 77
5.1 結論 77
5.2 未來展望 80
附錄 83
參考文獻 84
作者介紹 86

[1] Yasuoka, K., M. Matsumoto, and Y. Kataoka, “Evaporation and condensation at a liquid surface. I. Argon,” J. Chem. Phys., Vol. 101 , pp. 7904, 1994.
[2] A. Rytko¨nen, S. Valkealahti, and M. Manninen, “Melting and evaporation of argon clusters, ” J. Chem. Phys., Vol. 106, pp. 1888, 1997.
[3] Moseler, M., and Uzi Landman, 2000, “Formation, Stability, and Breakup of Nanojets,” Science, Vol. 289, pp.1165-1169.
[4] Eggers, J., “Dynamics of nanojets,” Phys. Rev. Lett., Vol. 89 , pp. 084502., 2002.
[5] Te-Hua Fang, Win-Jin Changb, and Shi-Cheng Liao,“Effects of temperature and aperture size on nanojet ejection process by molecular dynamics simulation,” Microelectronics Journal, Vol. 35 , pp. 687–691, 2004.
[6] Choi , Y. S., S. J. Kim, and M. U. Kim, "Molecular dynamics of unstable motions and capillary instability in liquid nanojets," Phys. Rev. E, Vol. 73, pp. 0163091-0163096, 2006.
[7] Levitt, M., Hirshberg, M., Sharon, R., Laidig, K.E., and Daggett, V. Calibration and Testing of a Water Model for Simulation of the Molecular Dynamics of Proteins and Nucleic Acids in Solution. J. Phys. Chem., B Vol. 25, pp. 5051-5061, 1997.
[8] Baskes, M. I., 1987, “Application of the Embedded-Atom Method to Covalent Materials: A Semiempirical Potential for Silicon,” Physical Review Letters, Vol. 59, pp. 2666-2669.
[9] Baskes, M. I., J. S. Nelson, and A. F. Wright, 1989, “Semiempirical Modified Embedded-Atom Potentials for Silicon and Germanium,” Physical Review B, Vol. 40, pp. 6085-6100.
[10]Baskes, M. I., 1992, “Modified Embedded-Atom Potentials for Cubic Materials and Impurities,” Physical Review B, Vol. 46, pp.2727-2742.
[11] Dou, Y., L. V. Zhigilei, N. Winograd, and B. J. Garrison, Explosive Boiling of Water Films Adjacent to Heated Surfaces: A Microscopic Description, J. Phys. Chem. A, Vol. 105, pp. 2748-2755, 2001.
[12] Dou, Y., N. Winograd, B. J. Garrison, and L. V. Zhigilei, “Substrate-assisted laser-initiated ejection of proteins embedded in water films, ” J. Phys. Chem. B, Vol. 107, pp. 2362-2365, 2003.
[13] Gallo, P., M. Rapinesi, and M. Rovere, “Confined water in the low hydration regime, ” Journal of Chemistry Physics, Vol. 117, pp. 369, 2002.
[14] Levitt, M., M. Hirshberg, R. Sharon, K.E. Laidig, and V. Daggett, “Calibration and Testing of a Water Model for Simulation of the Molecular Dynamics of Proteins and Nucleic Acids in Solution,” Journal of Physical Chemistry B, Vol. 101 , pp. 5051, 1997.
[15] Haile, J., “Molecular Dynamics Simulation: Elementary Methods, ” John Wiley & Sons, NY, 1992.
[16] Allen, M.P., and D.J. Tildesley, “Computer Simulation of Liquid, ” Clarendon Press, Oxford, 1991.
[17] Nosé, S.,“A unified formulation of the constant temperature molecular dynamics methods”, J.Chem. Phy., Vol. 81, pp.511-519, 1984.
[18] William G. Hoover, “Canonical dynamics： Equilibrium phase-space distributions”, Physical Review A. 31, pp.1695-1697, 1985.
[19] Rapaport, D. C., The Art of Molecular Dynamics Simulation, Cambridge University Press, London, 1997
[20] Goodfellow, J. M. et al, Molecular dynamics, CRC Press, Boston, 1990
[21] Frenkel, D. & B. Smit, Understanding Molecular Simulation, Academic Press, San Diego, 1996.
[22] Heermann, D. W., Computer Simulation Method, Springer-Verlag, Berlin, 1990
[23] Soper, A. K.; Phillips, M. G. , “A New determination of the structure of water at 25°C, ” Chem. Phys., Vol. 107, pp. 47, 1986.
[24] Lefebvre, A. H., “Gas Turbine Combustion,” Chapter 10, Hemisphere Publishing Corporation, New York, 1983.
[25] http://www.cs.sandia.gov/~sjplimp/lammps.html