臺灣博碩士論文加值系統

本實驗主要在研究磁流體於長寬比為一的Hele-Shaw cell流場中的自然對流現象。實驗中利用電阻式加熱片，由試片下方加熱的方式來產生自然對流，並外加垂直磁場，利用資料擷取系統坐熱傳值的量測，及使用紋影法來觀察磁場對本流場不穩定性的影響。從熱傳值的量測與紋影法的流場觀察發現外加垂直磁場對流場的不穩定性可加速流場不穩定性的發生，進而增進熱對流的效果有著顯著的影響。整個不穩定的流場模式未外加垂直磁場與有外加磁場的情大大不相同。

The nature convection of a magnetic fluid in a Hele-Shaw cell with aspect ratio of one was studied experimentally. The convection was induced by heating the cell at bottom. A vertical magnetic field opposite to the direction of gravity was also imposed. Results obtained from heat transfer measurements and shadowgraphs revealed that the vertically imposed magnetic field has destabizing influence. It enhanced the mature convection.

博碩士論文授權書 III
中文摘要 IV
ABSTRACT V
誌 謝 VI
目 錄 VII
圖目錄 IX
符號說明 XII
第一章 緒論 13
1.1文獻回顧 13
1.2研究動機 17
1.3磁性流體之構造 17
第二章 研究方法 19
2.1統御方程式 19
2.2實驗設備架構 21
2.2.1外加磁場 21
2.2.2流場夾持試片 21
2.2.3溫控系統 22
2.2.4資料擷取系統 23
2.2.5Hele-Shaw cell 24
2.2.6流場可視化系統 25
第三章 結果與討論 26
3.1磁性流體熱傳特性量測 26
3.1.1自動化量測初步結果 26
3.1.2資料擷取系統改良 27
3.1.3量測結果與數據分析方法 28
3.2流場可視化 30
第四章 結論與未來工作 32
參考文獻 34

1. Berkovsky, B.M. Magnetic Fluids Engineering Applications (Oxford Univ. Press, New York, 1993) pp. 214
2. Sihiliomis,M.I., “Magnetic Fluids,” Soviet Physics－Advances in Physical Science, Vol. 17, No.2,1974, pp.153-169.
3. Stiles,P.J.,and Kagan,M., “Thermocovective Instability of a Ferrofluid in a Strong Magnetic Field,” Journal of Collid and Interface Science, Vol.134, No.2, 1990, pp.435-488.
4. Blennerhassett, P. J., Lin, and Stiles, P. J., “Heat Transfer Through Strongly Magnetized Ferrofluids,” Proceedings of the Royal Society of London, Series A: Mathematical and Physical Science, Vol.433, No.1887, 1991,pp. 165-177.
5. Kato, Y., Kawai H., and Tanahashi, T., “Numerical Flow Analysis in a Cubic Cavity by the GSMAC Finite-Element Method,” Japan Society of Mechanical Engineers International Journal, Vol.33, No.41990, pp.649-658.
6. Blums, E., Cebers, A., and Maiorov, M. M., Magnetic Fluids, 1st ed., Walter de Gruyter, New York,1997,pp.289-341.
7. Finlayson, B.A., “Convective Instability of Ferromagnetic Fluids,” Journal of Fluid Mech., Vol.40, Pt. 4, 1970, pp.753-767.
8. Chandrasekhar, S., Hydrodynamic and Hydromagnetic Stability (Oxford: Clarendon, 1961)
9. Schwab, L, Magnetic Bénard Convection, Doctoral Dissertation, University of Munich, Germany, 1989.
10. Schwab, L., Hildebrandt, U., Stierstadt, K., “Magnetic Bénard Convection,” Journal of Magnetism and Magnetic Material, Vol.39, 1983, pp. 113-114.
11. Schwab, L., Stierstadt, K., “Field-Induced Wavevector-Selection by Magnetic Bénard Convection,” Journal of Magnetism and Magnetic Material, Vol.65, 1987, pp. 315-316.
12. Gotoh, K., Yamada, M., “Thermal Convecton in a Horizontal Layer of Magnetic Fluids,” Journal of the Physical Society of Japan, Vol. 51, No. 9, 1982, pp. 3042-3048.
13. Yamaguchi, H., Kobori, I., Uehata, Y., Shimada, K., “Natural Convection of Magnetic Fluid in a Rectangular Box,” Journal of Magnetism and Magnetic Material, Vol. 201, No 1-3, 1999, pp. 264-267.
14. Yamaguchi, H., Kobori, I., Uehata ., “Heat Transfer in Natural Convection of Magnetic Fluids,” Journal of Thermophysics and Heat Transfer, Vol.13, No 4, 1999, pp.501-507.
15. 張敏興,翁輝竹, “鐵磁流體在具軸向磁場之共軸旋轉圓柱中穩定性分析,” 中華民國第二十五屆全國力學會議論文集, pp. 649-660, 2001
16. Chen, C. Y., Wen, C. Y., “Numerical Simulations of Miscible Magnetic Flows in a Hele-Shaw Cell, Part I. Radial Flows,” Journal of Magnetism and Magnetic Matericals, accepted, 2001.
17. Wen, C. Y., Chen, C. Y, Yang, S. F., “Flow Visualization of Natural Convection of Magnetic Fluid in a Rectangular Hele-Shaw Cell,” Journal of Magnetism and Magnetic Matericals, accepted, 2001.
18. Tan, C., Homsy, G., “Stability of Miscible Displacements in Porous Media: Radial source flow,” Phys. Fluids 30(1987) pp. 1239-1245.