Hostname: page-component-78c5997874-g7gxr Total loading time: 0 Render date: 2024-11-09T13:42:01.115Z Has data issue: false hasContentIssue false

Countercurrent convection in a double-diffusive boundary layer

Published online by Cambridge University Press:  20 April 2006

R. H. Nilson
Affiliation:
S-Cubed, P.O. Box 1620, La Jolla, CA 92038

Abstract

Countercurrent flow may be induced by opposing buoyancy forces associated with compositional gradients and thermal gradients within a fluid. The occurrence and structure of such flows is investigated by solving the double-diffusive boundary-layer equations for steady laminar convection along a vertical wall of finite height. Non-similar solutions are derived using the method of matched asymptotic expansions, under the restriction that the Lewis and Prandtl numbers are both large. Two sets of asymptotic solutions are constructed, assuming dominance of one or the other of the buoyancy forces. The two sets overlap in the central region of the parameter space; each set matches up with neighbouring unidirectional similarity solutions at the respective borderlines of incipient counterflow.

Interaction between the buoyancy mechanisms is controlled by their relative strength R and their relative diffusivity Le. Flow in the outer thermal boundary layer deviates from single-diffusive thermal convection, depending upon the magnitude of the parameter RLe. Flow in the inner compositional boundary layer deviates from single-diffusive compositional convection, depending upon the magnitude of $RLe^{\frac{1}{3}}$.

Type
Research Article
Copyright
© 1985 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

Adams, J. A. & Mcfadden, P. W. 1966 Simultaneous heat and mass transfer in free convection with opposing buoyancy forces. AIChE J. 6, 584590.Google Scholar
Barenblatt, G. I. & Zeldovich, Ya. B. 1972 Self similar solutions as intermediate asymptotics. Ann. Rev. Fluid Mech. 4, 285312.Google Scholar
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, 3756.Google Scholar
Carey, V. P. & Gebhart, B. 1982a Transport near a vertical ice surface melting in saline water: some numerical calculations. J. Fluid Mech. 117, 379402.Google Scholar
Carey, V. P. & Gebhart, B. 1982b Transport near a vertical ice surface melting in saline water: experiments at low salinities. J. Fluid Mech. 117, 403424.Google Scholar
Cebeci, T. & Stewartson, K. 1983 On the calculation of separation bubbles. J. Fluid Mech. 133, 287296.Google Scholar
Chen, C. F. & Johnson, D. H. 1984 Double Diffusive Convection: a report on an Engineering Foundation Conference. J. Fluid Mech. 138, 405416.Google Scholar
Chen, C. F. & Turner, J. S. 1980 Crystallization in a double-diffusive system. J. Geophys. Res. 85, 25732593.Google Scholar
Chen, T. S. & Yuh, C. F. 1979 Combined heat and mass transfer in natural convection on an inclined plate. Numer. Heat Transfer 2, 233250.Google Scholar
Gebhart, B. & Pera, L. 1971 The nature of vertical natural convection resulting from combined buoyancy effects of thermal and mass diffusion. Intl J. Heat Mass Transfer 14, 20252050.Google Scholar
Hassan, M. M. & Eichhorn, R. 1979 Local nonsimilarity solutions for free convection flow and heat transfer from an inclined isothermal plate. Trans. ASME C: J. Heat Transfer 101, 642647.Google Scholar
Huppert, H. E. & Turner, J. S. 1981 Double-diffusive convection. J. Fluid Mech. 106, 299329.Google Scholar
Klemp, J. B. & Acrivos, A. 1972 A method of integrating the boundary layer equations through a region of reverse flow. J. Fluid Mech. 53, 171191.Google Scholar
Kuiken, H. K. 1968 An asymptotic solution for large Prandtl number free convection. J. Engng Maths. 2, 355371.Google Scholar
Kuiken, H. K. 1983 A class of backward free-convective boundary layer similarity solutions. Intl J. Heat Mass Transfer 26, 655661.Google Scholar
Mcbirney, A. R. 1980 Mixing and unmixing of magmas. J. Volcanol. Geothermal Res. 7, 357371.Google Scholar
Mcbirney, A. R. & Noyes, R. M. 1979 Crystallization and layering of the Skaergaard Intrusion. J. Petrology 20, 487554.Google Scholar
Minkowycz, W. J. & Sparrow, E. M. 1978 Numerical solution scheme for local nonsimilarity boundary layer analysis. Numer. Heat Transfer 1, 6985.Google Scholar
Nilson, R. H. 1981 Natural convective boundary layer on two dimensional and axisymmetric surfaces in high Prandtl number fluids. Trans. ASME C: J. Heat Transfer 103, 803807.Google Scholar
Nilson, R. H. & Baer, M. R. 1982 Double diffusive counterbuoyant boundary layer in laminar natural convection. Intl J. Heat Mass Transfer 25, 285287.Google Scholar
Nilson, R. H., Mcbirney, A. R. & Baker, B. H. 1985 Liquid fractionation – part II: fluid dynamics and quantitative implications for magmatic systems. J. Volcanol. Geothermal Res. 24, 2554.Google Scholar
Ostrach, S. 1980 Physico-Chem. Hydrodyn. 1, 233247.
Romero, L. A. 1982 Nonexistence of solutions for certain double-diffusive counterbuoyant boundary layer flows. Internal memo to A. R. Reed, Sandia Natl Labs, Albuquerque, NM (22 October).
Sammakia, B. & Gebhart, B. 1983 Transport near a vertical ice surface melting in water of various salinity levels. Intl J. Heat Mass Transfer 26, 14391452.Google Scholar
Saville, D. A. & Churchill, S. W. 1970 Simultaneous heat and mass transfer in free convection boundary layers. AIChE J. 16, 268273.Google Scholar
Shaw, H. R. 1974 Diffusion of H2O in granitic liquids. Part I: experimental data. Part II: mass transfer in magma chambers. In Geochemical Transport and Kinetics (ed. A. W. Hoffman, B. M. Giletti, H. S. Yoder & R. A. Yund), Carnegie Inst. Washington Publ. 634, pp. 139170.
Sparrow, E. M., Quack, H. & Boerner, C. J. 1970 Local nonsimilarity boundary layer solutions. AIAA J. 8, 19361942.Google Scholar
Sparrow, E. M. & Yuh, H. S. 1971 Local nonsimilarity thermal boundary layer solutions. Trans. ASME C: J. Heat Transfer 96, 328334.Google Scholar
Turner, J. S. 1974 Double-diffusive phenomena. Ann. Rev. Fluid Mech. 6, 3756.Google Scholar
Turner, J. S. 1980 A fluid dynamical model of differentiation and layering in magma chambers. Nature 285, 213215.Google Scholar
Veldman, A. E. P. 1980 On a generalized Falkner Skan equation. J. Math. Anal. Applics 75, 102111.Google Scholar
Walin, G. 1971 Contained non-homogeneous flow under gravity or how to stratify a fluid in the laboratory. J. Fluid Mech. 48, 647672.Google Scholar
Wilcox, W. R. 1961 Simultaneous heat and mass transfer in free convection. Chem. Engng Sci. 13, 113119.Google Scholar