Experimental Determination of Heat Transfer Coefficients in Water Flowing over a Horizontal Ice Sheet
Experiments to study the melting of a horizontal ice sheet with a flow of water above it were conducted in a 35 m long refrigerated flume with a cross section of 1.2x1.2 m. Water depth, temperature, and velocity were varied as well as the temperature and initial surface profile of the ice sheet. The...
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ftdtic:ADA170427 2023-05-15T16:40:15+02:00 Experimental Determination of Heat Transfer Coefficients in Water Flowing over a Horizontal Ice Sheet Lunardini,V. J. Zisson,J. R. Yen,Y. C. COLD REGIONS RESEARCH AND ENGINEERING LAB HANOVER NH 1986-06 text/html http://www.dtic.mil/docs/citations/ADA170427 http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA170427 en eng http://www.dtic.mil/docs/citations/ADA170427 APPROVED FOR PUBLIC RELEASE DTIC AND NTIS Thermodynamics *HEAT TRANSFER *WATER *ICE *CHANNEL FLOW COMPUTER PROGRAMS TURBULENCE DATA REDUCTION TABLES(DATA) CONVECTION(HEAT TRANSFER) REYNOLDS NUMBER HEAT SINKS HEAT TRANSFER COEFFICIENTS Grashof number Text 1986 ftdtic 2016-02-21T02:11:58Z Experiments to study the melting of a horizontal ice sheet with a flow of water above it were conducted in a 35 m long refrigerated flume with a cross section of 1.2x1.2 m. Water depth, temperature, and velocity were varied as well as the temperature and initial surface profile of the ice sheet. The heat transfer regimes were found to consist of forced turbulent flow at high Reynolds numbers with a transition to free convection heat transfer. There was no convincing evidence of a forced laminar regime. The data were correlated for each of the regimes, with the Reynolds number, Re, or the Grashof number combined with the Reynolds number as Gr/Re to the 2.5 power used to characterize the different kinds of heat transfer. For water flowing over a horizontal ice sheet, the melting heat flux, for low flow velocities, was not found to drop below the value for the free convection case-488.5 W/sq m-as long as the water temperature exceeds 3.4 C. This is significant since the free convection melt values far exceed those for laminar forced convection. At the low flow velocities, the melting flux was not dependent upon the fluid temperature until the water temperature dropped below 3.4 C, when q sub c = 135.7 (Delta T). In general, the heat transfer was found to significantly exceed that of non-melting systems for the same regimes. This was attributed to increased free stream turbulence, thermal instability due to the density maximum of water near 4 C, and the turbulent eddies associated with the generation of a wavy ice surface during the melting. Text Ice Sheet Defense Technical Information Center: DTIC Technical Reports database |
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Open Polar |
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Defense Technical Information Center: DTIC Technical Reports database |
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ftdtic |
language |
English |
topic |
Thermodynamics *HEAT TRANSFER *WATER *ICE *CHANNEL FLOW COMPUTER PROGRAMS TURBULENCE DATA REDUCTION TABLES(DATA) CONVECTION(HEAT TRANSFER) REYNOLDS NUMBER HEAT SINKS HEAT TRANSFER COEFFICIENTS Grashof number |
spellingShingle |
Thermodynamics *HEAT TRANSFER *WATER *ICE *CHANNEL FLOW COMPUTER PROGRAMS TURBULENCE DATA REDUCTION TABLES(DATA) CONVECTION(HEAT TRANSFER) REYNOLDS NUMBER HEAT SINKS HEAT TRANSFER COEFFICIENTS Grashof number Lunardini,V. J. Zisson,J. R. Yen,Y. C. Experimental Determination of Heat Transfer Coefficients in Water Flowing over a Horizontal Ice Sheet |
topic_facet |
Thermodynamics *HEAT TRANSFER *WATER *ICE *CHANNEL FLOW COMPUTER PROGRAMS TURBULENCE DATA REDUCTION TABLES(DATA) CONVECTION(HEAT TRANSFER) REYNOLDS NUMBER HEAT SINKS HEAT TRANSFER COEFFICIENTS Grashof number |
description |
Experiments to study the melting of a horizontal ice sheet with a flow of water above it were conducted in a 35 m long refrigerated flume with a cross section of 1.2x1.2 m. Water depth, temperature, and velocity were varied as well as the temperature and initial surface profile of the ice sheet. The heat transfer regimes were found to consist of forced turbulent flow at high Reynolds numbers with a transition to free convection heat transfer. There was no convincing evidence of a forced laminar regime. The data were correlated for each of the regimes, with the Reynolds number, Re, or the Grashof number combined with the Reynolds number as Gr/Re to the 2.5 power used to characterize the different kinds of heat transfer. For water flowing over a horizontal ice sheet, the melting heat flux, for low flow velocities, was not found to drop below the value for the free convection case-488.5 W/sq m-as long as the water temperature exceeds 3.4 C. This is significant since the free convection melt values far exceed those for laminar forced convection. At the low flow velocities, the melting flux was not dependent upon the fluid temperature until the water temperature dropped below 3.4 C, when q sub c = 135.7 (Delta T). In general, the heat transfer was found to significantly exceed that of non-melting systems for the same regimes. This was attributed to increased free stream turbulence, thermal instability due to the density maximum of water near 4 C, and the turbulent eddies associated with the generation of a wavy ice surface during the melting. |
author2 |
COLD REGIONS RESEARCH AND ENGINEERING LAB HANOVER NH |
format |
Text |
author |
Lunardini,V. J. Zisson,J. R. Yen,Y. C. |
author_facet |
Lunardini,V. J. Zisson,J. R. Yen,Y. C. |
author_sort |
Lunardini,V. J. |
title |
Experimental Determination of Heat Transfer Coefficients in Water Flowing over a Horizontal Ice Sheet |
title_short |
Experimental Determination of Heat Transfer Coefficients in Water Flowing over a Horizontal Ice Sheet |
title_full |
Experimental Determination of Heat Transfer Coefficients in Water Flowing over a Horizontal Ice Sheet |
title_fullStr |
Experimental Determination of Heat Transfer Coefficients in Water Flowing over a Horizontal Ice Sheet |
title_full_unstemmed |
Experimental Determination of Heat Transfer Coefficients in Water Flowing over a Horizontal Ice Sheet |
title_sort |
experimental determination of heat transfer coefficients in water flowing over a horizontal ice sheet |
publishDate |
1986 |
url |
http://www.dtic.mil/docs/citations/ADA170427 http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA170427 |
genre |
Ice Sheet |
genre_facet |
Ice Sheet |
op_source |
DTIC AND NTIS |
op_relation |
http://www.dtic.mil/docs/citations/ADA170427 |
op_rights |
APPROVED FOR PUBLIC RELEASE |
_version_ |
1766030641533550592 |