Abo Bibliothek: Guest
Digitales Portal Digitale Bibliothek eBooks Zeitschriften Referenzen und Berichte Forschungssammlungen
Journal of Enhanced Heat Transfer
Impact-faktor: 0.562 5-jähriger Impact-Faktor: 0.605 SJR: 0.211 SNIP: 0.361 CiteScore™: 0.33

ISSN Druckformat: 1065-5131
ISSN Online: 1026-5511

Volumes:
Volumen 26, 2019 Volumen 25, 2018 Volumen 24, 2017 Volumen 23, 2016 Volumen 22, 2015 Volumen 21, 2014 Volumen 20, 2013 Volumen 19, 2012 Volumen 18, 2011 Volumen 17, 2010 Volumen 16, 2009 Volumen 15, 2008 Volumen 14, 2007 Volumen 13, 2006 Volumen 12, 2005 Volumen 11, 2004 Volumen 10, 2003 Volumen 9, 2002 Volumen 8, 2001 Volumen 7, 2000 Volumen 6, 1999 Volumen 5, 1998 Volumen 4, 1997 Volumen 3, 1996 Volumen 2, 1995 Volumen 1, 1994

Journal of Enhanced Heat Transfer

DOI: 10.1615/JEnhHeatTransf.v14.i3.30
pages 209-221

Mechanism for Nucleation Jet Enhancement of Nucleate Pool Boiling

David Christopher
Key Laboratory for Thermal Science and Power Engineering of Ministry of Education Department of Energy and Power Engineering, Tsinghua University, Beijing, 100084, China
H. Wang
School of Mechanical Engineering, Purdue University, W. Lafayette, IN, 47906, USA

ABSTRAKT

The very high heat transfer rates in nucleate pool boiling are due to the rapid vapor bubble formation and departure from the heated surface. This paper presents observations and analyses of high-frequency bubble departures from very thin wires. The analysis shows that the bubbles entrained in experimentally observed nucleation jets were already at the stage of heat transfer-controlled growth when they were rapidly ejected from the surface. The momentum in the expanding liquid around the bubble, perhaps augmented by natural convection from the heated surface, most likely pulls the bubbles from the surface into the jet flow. The jet flows themselves are shown to be not due to the rising of the bubbles in the liquid because the bubbles are very small so their buoyancy was much less than the drag at the observed velocities of 120 mm/s. The jet streams were postulated to be due to the bubble growth in a relatively large cavity (similar in size to the observed bubble diameter of about 6 μm first observed about 0.2 mm above the surface) that channeled the liquid flow driven by the bubble growth in the vertical direction. The pulsed jet flows caused by the rapid bubble growth and frequent departures increase the convection heat transfer inside the cavities in addition to increasing the convection along the surface outside the cavities due to entrainment of additional liquid into the jets that increases the heat transfer along the surface.


Articles with similar content:

ENHANCED HEAT TRANSFER FROM NUCLEATION JETS DURING NUCLEATE POOL BOILING
International Heat Transfer Conference 13, Vol.0, 2006, issue
H. Wang, David Christopher
OBSERVATION OF COALESCENCE BEHAVIORS OF MULTIPLE NUCLEATION BUBBLES IN SUBCOOLED FLOW BOILING
First Thermal and Fluids Engineering Summer Conference, Vol.15, 2015, issue
Tomoaki Kunugi, Yang Cao, Zensaku Kawara, Takehiko Yokomine
AXIAL PROPAGATION OF FREE SURFACE BOILING INTO SUPERHEATED LIQUIDS IN VERTICAL TUBES
International Heat Transfer Conference 5, Vol.6, 1974, issue
Michael A. Grolmes , Hans K. Fauske
Abstract of "A PORE TRAPPED IN SOLID DURING SOLIDIFICATION"
ICHMT DIGITAL LIBRARY ONLINE, Vol.1, 2000, issue
Y. K. Kuo, S. H. Chiu, P. S. Wei
A PORE TRAPPED IN SOLID DURING SOLIDIFICATION
ICHMT DIGITAL LIBRARY ONLINE, Vol.1, 2000, issue
Y. K. Kuo, S. H. Chiu, P. S. Wei