脈動式熱管（PHP）是一種新型態兩相流熱傳裝置，其結合了潛熱與顯熱的高熱傳性質，加上構造簡單，並擁有可彎曲的特性，是一項相當具有前景的熱傳裝置。依目前文獻可知，影響脈動式熱管效能參數眾多，本文旨在嘗試利用外徑1/8英吋，內徑2mm之紅銅管以及外徑3mm，內徑2mm之玻璃管作為閉迴路型脈動式熱管之管路，以水作為工作流體填充於管內，藉此架構進行(1)流場可視化觀測；(2)脈動式熱管熱傳性能分析及(3)脈動式熱管與傳統毛細式熱管性能評比。其結果(1)管內流場的型態會隨著熱負荷的多寡而改變，流場可分為震盪期、過渡期與穩定期；(2)系統總熱阻會隨著熱負荷的增加而遞減，填充比率為30%時，PHP熱傳效率最佳，而依照擺設傾斜角度的不同，影響脈動式熱管運作與效能之主要實驗參數也隨之改變，此結果可提供設計者製作閉迴路型脈動式熱管的參考；(3)依據脈動式熱管與熱管性能評比實驗模組以相同的吸熱與散熱表面積於垂直與水平的擺設方位，評比脈動式熱管與熱管之性能，實驗結果為脈動式於垂直擺設條件下如能進入至穩定期，其效能可優於熱管。

Pulsating heat pipe (PHP) is a newly developed two-phase-flow heat transfer device, which can transfer heat very efficiently in both sensible and latent forms. Due to the simple structure and the bent characteristics, PHP becomes a prosperous heat transfer machine. The purpose of this study is to build several closed-loop PHPs made by copper tube (outer diameter 1/8”, inner diameter 2mm) or glass tube (outer diameter 3mm, inner diameter 2mm), which is partially filled with a working fluid such as water. Based on the above developed PHP, the experiments were conducted as follows: (1) to observe visualization of flow pattern inside the PHP tube, (2) to measure the thermal transport performance of PHPs, and (3) to compare the performance of PHP and traditional heat pipe (THP). The experimental results show that (1) the type of flow pattern inside the PHP tube depends on the input heat loading. It was found that the flow pattern changes from the oscillating to transiting and then to stable period with increasing input heat loading; (2) the thermal resistance of PHP decreases with increasing heat loading. In addition, when the filling ratio is equal to 30%, it reaches the best heat transfer efficiency. When the angle of inclination changes, main parameter that effects efficiency of PHP, will be different; and (3) in case that both heat loading and area of heat transfer surface are equal, PHP may have the better heat transfer efficiency than THP at the vertical operating condition.

[1]Suo, M., Griffith, P.,“Two-Phase Flow in Capillary
Tubes,”Transactions of the ASME, pp. 576-582,September,
1964.

[2]Akachi, H.,“Looped Capillary Heat Pipe,”Japanese
Patent, No. Hei6- 97147, 1994.

[3]Hosoda, M., Nishio, S. and Shirakashi, R.,“Meandering
Closed –Loop Heat-Transport Tube (Propagation Phenomena
of Vapor Plug),” Proceedings of the 5th ASME/JSME Joint
Thermal Engineering Conference, San Diego, CA., March,
pp.15-19, 1999.

[4]Nagata, S., Shirakashi, R. and Nishio, S., “Closed-Loop
Heat-Transport Tube,”第三十六回日本熱傳演講論文集, pp.
675-676, 1999.

[5]Schneider, M., Khandekar, S., Sch□fer, P., Kulenovic,
R. and Groll, M.,“Visualisation of Thermofluiddynamic
Phenomena in Flat Plate Closed Loop Pulsating Heat
Pipes,” Proceedings of the 6th International Heat Pipe
Symposium, Chiang Mai, Thailand, pp. 5-9, November, 2000.

[6]Khandekar, S., Groll, M., Charoensawan, P. and Terdtoon,
P.,“Pulsating Heat Pipes:Thermo-fluidic Characteristics
and Comparative Study with Single-Phase Thermosyphon",
Proceedings 12th International Heat Transfer Conference
, Grenoble, France, pp. 459-464, 2002.

[7]Kiseev, V. M. and Zolkin, K. A.,“The Influence of
Acceleration on The Perf-Romance of Oscillating Heat
Pipes,”Proceedings of 11th International Heat Pipe
Conference, Tokyo, Japan, pp. 154-158, 1999.

[8]Gu, J., Kawaji, M. and Futamata, R.,“Effects of Gravity
on the Performanace of Pulsating Heat Pipes,”Journal of
Thermophysics and Heat Transfer, vol. 18, No. 3, pp. 370-
378, July-September, 2004.

[9]Akachi, H., Polasek, F. and Stulc, P.,“Pulsating Heat
Pipes,”Proceedings of the 5th International Heat Pipe
Symposium, Melbourne, Australia, pp. 208-217, 1996.

[10]Doboson, R. T. and Harms, T. M.,“Lumped Parameter
Analysis of Close and Open Oscillatory Heat Pipes,”
Proceedings of 11th International Heat Pipe Conference,
Tokyo, Japan, pp. 137-142, 1999.

[11]Maezawa, S., Izumi, T. and Gi, K.,“Experimental Chaos
in Oscillating Capillary Tube Heat Pipes,”10th
International Heat Pipe Conference, Stuttgart, pp. 21-
25, September, 1997.

[12]Lee, W. H., Jung, H. S., Kim, J. H. and Kim, J. S.,
“Flow Visualization of Oscillating Capillary Tube Heat
Pipe,”Proceedings of the 11th International Heat Pipe
Conference, Japan Association for Heat Pipes, Tokyo,
Japan, pp. 131-136, 1999.

[13]Charoensawan, P., Terdtoon, P., Tantakom, P., Ingsuwan,
P. and Groll, M.,“Effects of Inclination Angles,
Filling Ratios and Total Lengths on Heat Transfer
Characteristics of A Closed-Loop Oscillating Heat
Pipe,”Preprints of the 6th International Heat Pipe
Symposium, Chiang Mai, Thailand, pp. 5-9, November,
2000.

[14]Groll, M. and Khandekar, S., “Pulsating Heat Pipes: A
Challenge and Still Unsolved Problem in Heat Pipe
Science,” Proceedings of the 3rd International
Conference on Transport Phenomena in Multiphase
Systems, Kielce, Poland, pp. 35-44, 2002.

[15]Wong, T. N., Tong, B. Y., Lim, S. M., Ooi, K. T.,
“Theoretical Modelling of Pulsating Heat Pipe,”11th
International Heat Pipe Conference, Tokyo, pp. 12-16,
September, 1999.

[16]Maezawa, S., Sato, F. and Gi, K.,“Chaotic Dynamics of
Looped Oscillating Heat Pipes,”Preprints of the 6th
International Heat Pipe Symposium, Chiang Mai, pp. 5-9,
November, 2000.

[17]Zuo, Z. J., North, M. T. and Ray, L.,“Combined
Pulsating and Capillary Heat Pipe Mechanism for
Cooling of High Heat Flux Electronics,”
http://www.thermacore.com, 2001.

[18]Zhang, Y., Faghri, A.,“Heat Transfer of Pulsating Heat
Pipe with Open End ,” International Journal of Heat
and Mass Transfer, Vol. 45, No. 12, pp. 755-764, 2002.

[19]Zhang, Y., Faghri, A., Shafii, M. B., “Analysis of
Liquid-Vapor Pulsating Flow in a U-Shaped Miniature
Tube,” International Journal of Heat and Mass Transfer
, Vol. 45, No. 12, pp. 2501-2508, 2002.

[20]Zhang, Y. and Faghri, A.,“Oscillatory Flow in
Pulsating Heat Pipes with Arbitrary Numbers of
Turns,”Journal of Thermophysics and Heat Transfer,
Vol. 17, No. 3, pp. 340-347, July -September, 2003.

[21]Akachi, H. and Miyazaki, Y.,“Stereo-Type Heat Lane
Heat Sink,”10th International Heat Pipe Conference,
Stuttgart, pp. 21-25, September, 1997.

[22]Gi, K., Maezawa, K. Y. and Yamazaki, N.,“CPU Cooling
of Notebook PC by Oscillating Heat Pipe,” Proceedings
of the 11th International Heat Pipe Conference, Japan
Association for Heat Pipes, Tokyo, Japan, pp. 166-169,
1999.

[23]Rittidech, S., Terdtoon, P., Murakami, M., Kamonpet,
P., Jompakdee, W.,“Correlation to Predict Heat
Transfer Characteristics of a Closed-end Oscillating
Heat Pipe at Normal Operating Condition”, Applied
Thermal Engineering, pp. 497-510, 2003.

[24]Groll, M. and Khanderkar, S.,“On the Definition of
Pulsating Heat Pipe: An Overview,”Proceedings of the
5th Minsk International Seminar, Minsk, Belarus, 2003.

[25]Collier, J. G. and Thome, J. R., Convective Boiling and
Condensation, 3rd Ed., 1996.

[26]Wallis, G.,“One Dimensional Two Phase Flow,”McGraw
Hill, 1969.

[27]Khandekar, S., Schneider, M., Schafer, P., Kulenovic,
R. and Groll, M.,“Thermofluid Dynamic Study of Flat
Plate Closed Loop Pulsating Heat Pipes,”Microscale
Thermophysical Engineering, Vol. 6 ,Issue 4, pp. 303-
318, 2002.

[28]Khandekar, S., Groll, M., “Pulsating Heat Pipes: Study
on a Two-Phase Loop,”13th International Conference on
Thermal Enerieering and Thermogrammetry, Budapest,
Hungary, pp.18-20 June, 2003.

[29]Khandekar S., Dollinger N. and Groll M.,“Understanding
Operational Regimes of Pulsating Heat Pipes: An
Experimental Study,” Applied Thermal Engineering,
Elsevier Science, Vol. 23/6, pp. 707-719, 2003.

[30]White, E. and Beardmore, R.,“The Velocity of Rise of
Single Cylindrical Air Bubbles Through Liquids
Contained in Vertical Tubes,”Chem. Engg. Science, Vol.
17, pp. 351-361, 1962.