Hostname: page-component-78c5997874-94fs2 Total loading time: 0 Render date: 2024-11-05T15:29:41.022Z Has data issue: false hasContentIssue false

Transport near a vertical ice surface melting in saline water: some numerical calculations

Published online by Cambridge University Press:  20 April 2006

Van P. Carey
Affiliation:
Department of Mechanical and Aerospace Engineering, State University of New York at Buffalo, Amherst, NY 14260, U.S.A.
Benjamin Gebhart
Affiliation:
Department of Mechanical Engineering and Applied Mechanics, University of Pennsylvania, Philadelphia, PA 19104, U.S.A.

Abstract

Computed numerical results are presented for the laminar buoyancy-induced flows driven by combined thermal and saline transport near a vertical melting ice surface in saline water. Results are presented which indicate that conventional boundary-layer flow occurs for some combinations of ambient salinity and temperature in the ranges 0 to 31‰ and −1 to 20°C, respectively. These conditions are very common in terrestrial waters. The analysis used herein is the first to model fully the many complicated aspects of these flows. The present analysis includes simultaneous transport of salt and thermal energy as well as the effect of interface motion. The formulation uses the most recently available transport properties and a very accurate equation of state for the density of pure and saline water. The interface temperature and salinity, which are not known a priori, are here determined jointly from the transport equations, and from species-conservation and phase-equilibrium relations at the ice surface. At low ambient temperatures, the flow is found to be dominated by the upward saline buoyancy, resulting in upward flow. However, at high temperatures and low salinities, the downward thermal buoyancy overcomes the upward saline buoyancy near the surface to cause downward flow. For choices of ambient conditions between these extremes, the opposing saline and thermal buoyancy are about equal in strength. The resulting tendency for bi-directional flow at these intermediate circumstances caused numerical stability problems which made it impossible to obtain convergent solutions for some cases. However, calculated solutions were obtained at ambient salinities below 5‰, for ambient temperatures between 8 and 20°C, and at temperatures below 4°C, for ambient salinities between 0 and 31‰. These solutions indicate the limits of the range of conditions for which laminar boundary layer flow occurs. They further suggest that outside these ranges, the flow may be laminar and bi-directional. The very strong buoyancy which characterizes some of these conditions suggests that they may become turbulent at short downstream distances. The computed results are seen to be in excellent agreement with the limited experimental data and observations of previous studies.

Type
Research Article
Copyright
© 1982 Cambridge University Press

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Carey, V. P. 1981 Transport in vertical mixed convection flows and natural convection flows in cold water. Ph.D. thesis, State University of New York at Buffalo.
Carey, V. P. & Gebhart, B. 1981 Visualization of the flow adjacent to a vertical ice surface melting in cold pure water. J. Fluid Mech. 107, 3755.Google Scholar
Carey, V. P. & Gebhart, B. 1982 Transport near a vertical ice surface melting in saline water: experiments at low salinities. J. Fluid Mech. 117, 403423.Google Scholar
Carey, V. P., Gebhart, B. & Mollendorf, J. C. 1980 Buoyancy force reversals in vertical natural convection flows in cold water. J. Fluid Mech. 97, 279297.Google Scholar
Fujino, K., Lewis, E. L. & Perkin, R. G. 1974 The freezing point of sea water at pressures up to 1000 bars. J. Geophys. Res. 79, 17921797.Google Scholar
Gebhart, B. & Mollendorf, J. C. 1977 A new density relation for pure and saline water. Deep-Sea Res. 24, 831848.Google Scholar
Gebhart, B. & Mollendorf, J. C. 1978 Buoyancy-induced flows in water under conditions in which density extrema may arise. J. Fluid Mech. 89, 673707.Google Scholar
Huppert, H. E. & Turner, J. S. 1978 On melting icebergs. Nature 271, 4648.Google Scholar
Johnson, R. S. 1978 Transport from a melting vertical ice slab in saline water. M.S. thesis, State University of New York at Buffalo.
Josberger, E. G. 1979 Laminar and turbulent boundary layers adjacent to melting vertical ice walls in salt water. Scientific Rep. no. 16, Office of Naval Research.Google Scholar
Josberger, E. G. & Martin, S. 1981 A laboratory and theoretical study of the boundary layer adjacent to a vertical melting ice wall in salt water. J. Fluid Mech. 111, 439473.Google Scholar
Marschall, E. 1977 Free convection melting on glacial ice in saline water. Lett. Heat Mass Transfer 4, 381384.Google Scholar
Mollendorf, J. C., Kukulka, D. & Gebhart, B. 1982 Transport properties of seawater (in preparation).
Neshyba, S. & Josberger, E. G. 1980 On the estimation of antarctic iceberg melt rate. J. Phys. Oceanog. 10, 16811685.Google Scholar
Stewartson, K. & Jones, L. T. 1957 The heated vertical plate at high Prandtl number. J. Aero. Sci. 24, 379380.Google Scholar
Vanier, C. R. & Tien, C. 1968 Effect of maximum density and melting on natural convection heat transfer from a vertical plate. Chem. Engng Prog. Symp. Series 64, 240254.Google Scholar
Wilson, N. W. & Vyas, B. D. 1979 Velocity profiles near a vertical ice surface melting into fresh water. Trans. A.S.M.E. C, J. Heat Transfer 101, 313317.Google Scholar