CONDENSED MATTER: STRUCTURE, MECHANICAL AND THERMAL PROPERTIES |
|
|
|
|
Transition to Film Boiling in Microgravity: Influence of Subcooling |
ZHAO Jian-Fu, LI Jing, YAN Na, WANG Shuang-Feng |
Key Laboratory of Microgravity (National Microgravity Laboratory), Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190 |
|
Cite this article: |
ZHAO Jian-Fu, LI Jing, YAN Na et al 2010 Chin. Phys. Lett. 27 076401 |
|
|
Abstract The transition process to film pool boiling in microgravity is studied experimentally aboard the Chinese recoverable satellite SJ-8. A quasi-steady heating method is adopted, in which the heating voltage is controlled to increase exponentially with time. Small, primary bubbles are formed and slid on the surface, which coalesce with each other to form a large coalesced bubble. Two ways are observed for the transition from nucleate to film boiling at different subcoolings. At high subcooling, the coalesced bubble with a smooth surface grows slowly. It is then difficult for the coalesced bubble to cover the whole heater surface, resulting in a special region of transition boiling in which nucleate boiling and local dry areas can coexist. In contrast, strong oscillation of the coalesced bubble surface at low subcooling may cause rewetting of local dry areas and activation of more nucleate sites, resulting in an abrupt transition to film boiling.
|
Keywords:
64.70.Fh
44.35.+c
|
|
Received: 14 October 2009
Published: 28 June 2010
|
|
PACS: |
64.70.fh
|
(Boiling and bubble dynamics)
|
|
44.35.+c
|
(Heat flow in multiphase systems)
|
|
|
|
|
[1] Straub J 2001 Adv. Heat Transfer 35 57 [2] Di Marco P 2003 J. Jpn. Microgravity Appl. 20 252 [3] Kim J 2003 J. Jpn. Microgravity Appl. 20 264 [4] Ohta H 2003 J. Jpn. Microgravity Appl. 20 272 [5] Zhao J F 2010 Int. J. Multiphase Flow 36 135 [6] Zhao J F, Li J, Yan N and Wang S F 2009 Microgravity Sci. Technol. 21 S175 [7] Johnson H A 1971 Int. J. Heat Mass Transfer 14 67 [8] Oka T, Abe Y, Mori Y H and Nagashima A 1995 J. Heat Transfer Trans. ASME 117 408 [9] Lee H S, Merte H and Chiaramonte F 1997 J. Thermophy. Heat Transfer 11 216
|
|
Viewed |
|
|
|
Full text
|
|
|
|
|
Abstract
|
|
|
|
|