Hostname: page-component-7479d7b7d-t6hkb Total loading time: 0 Render date: 2024-07-11T09:27:34.939Z Has data issue: false hasContentIssue false

The effect of rotation on double-diffusive convection in a laterally heated vertical slot

Published online by Cambridge University Press:  26 April 2006

Oliver S. Kerr
Affiliation:
City University, Northampton Square, London EC1V OHB, UK

Abstract

The effect of rotation about a vertical axis on the linear stability of a salt-stratified fluid enclosed in a vertical slot when subjected to a temperature difference between the walls is investigated. It is found that for large salinity stratifications there are three distinct regimes of instability for different values of the rotation rate. For small rotation rates the convection cells resemble the thin, almost flat, convection cells predicted by non-rotating theory. The effect of the rotation is to marginally destabilize the fluid whilst inducing a small slope in the convection cells along the parallel walls. As the rotation rate is increased there is an abrupt change in the form of the most unstable convection cells as their aspect ratio and slope parallel to the walls both become of order one in magnitude. As the rotation rate is further increased there is a second less abrupt transition when the internal Rossby radius of deformation based on the vertical scale of the cells becomes of the same order of size as the slot width. After this point the slope of the cells increases in proportion to the rotation rate. The asymptotic nature of these three regimes is found.

The effect of rotation on double-diffusive instabilities caused by more general horizontal temperature and salinity gradients in a salt-stratified fluid is also investigated, with particular reference to the case of heating the salinity gradient from a single sidewall. This analysis is restricted to the case where the rotation rate is low.

Type
Research Article
Copyright
© 1995 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

Chen, C. F., Briggs, R. A. & Wirtz, D. G. 1971 Stability of thermal convection in a salinity gradient due to lateral heating. Intl J. Heat Mass Transfer 14, 5765.Google Scholar
Chen, C. F. & Sandford, R. D. 1977 Stability of time-dependent double-diffusive convection in an inclined slot. J. Fluid Mech. 83, 8395.Google Scholar
Chen, C. F. & Skok, M. W. 1974 Cellular convection in a salinity gradient along a heated inclined wall. Intl J. Heat Mass Transfer 17, 5160.Google Scholar
Chereskin, T. K. & Linden, P. F. 1986 The effect of rotation on intrusions produced by heating a salinity gradient. Deep-Sea Res. 33, 305322.Google Scholar
Gill, A. E. 1982 Atmosphere-Ocean Dynamics. Academic Press.
Hart, J. E. 1971 On sideways diffusive instability. J. Fluid Mech. 49, 279288.Google Scholar
Hart, J. E. 1973 Finite amplitude sideways diffusive convection. J. Fluid Mech. 59, 4764.Google Scholar
Holyer, J. Y. 1983 Double-diffusive interleaving due to horizontal gradients. J. Fluid Mech. 137, 347362.Google Scholar
Holyer, J. Y., Jones, T. J., Priestly, M. G. & Williams, N. C. 1987 The effect of vertical temperature and salinity gradients on double-diffusive interleaving. Deep-Sea Res. 34, 517530.Google Scholar
Huppert, H. E. & Josberger, E. G. 1980 The melting of ice in cold stratified water. J. Phys. Oceanogr. 10, 953960.Google Scholar
Huppert, H. E. & Turner, J. S. 1980 Ice blocks melting into a salinity gradient. J. Fluid Mech. 100, 367384.Google Scholar
Kerr, O. S. 1989 Heating a salinity gradient from a vertical sidewall: linear theory. J. Fluid Mech. 207, 323352.Google Scholar
Kerr, O. S. 1990 Heating a salinity gradient from a vertical sidewall: nonlinear theory. J. Fluid Mech. 217, 529546.Google Scholar
Kerr, O. S. & Holyer, J. Y. 1986 The effect of rotation on double-diffusive interleaving. J. Fluid Mech. 162, 2333.Google Scholar
Linden, P. F. & Weber, J. E. 1977 The formation of layers in a double-diffusive system with a sloping boundary. J. Fluid Mech. 81, 757773.Google Scholar
Mcdougall, T. J. 1985 Double-diffusive interleaving I. Linear stability analysis. J. Phys. Oceanogr. 15, 15321541.Google Scholar
Niino, H. 1986 A linear theory of double-diffusive horizontal intrusions in a temperature-salinity front. J. Fluid Mech. 171, 71100.Google Scholar
Paliwal, R. C. & Chen, C. F. 1980 Double-diffusive instability in an inclined fluid layer. Part 2. Stability analysis. J. Fluid Mech. 98, 769785.Google Scholar
Pearlstein, A. J. 1981 effect of rotation on the stability of a doubly diffusive fluid layer. J. Fluid Mech. 103, 389412.Google Scholar
Posmentier, E. S. & Hibbard, C. B. 1982 The role of tilt in double-diffusive interleaving. J. Geophys. Res. 87, 518524.Google Scholar
Rayleigh, Lord 1883 Investigation of the character of the equilibrium of an incompressible heavy fluid of variable density. Proc. Lond. Math. Soc. 14, 170177.Google Scholar
Ruddick, B. R. 1992 Intrusive mixing in a Mediterranean salt lens – Intrusion slopes and dynamical mechanisms. J. Phys. Oceanogr. 22, 12741285.Google Scholar
Ruddick, B. R. & Turner, J. S. 1979 The vertical length scale of double-diffusive intrusions. Deep-Sea Res. 26, 903913.Google Scholar
Schladow, S. G., Thomas, E. & Koseff, J. R. 1992 The dynamics of intrusions into a thermohaline stratification. J. Fluid Mech. 236, 127165.Google Scholar
Stern, M. E. 1967 Lateral mixing of water masses. Deep-Sea Res. 14, 747753.Google Scholar
Tanny, J. & Tsinober, A. B. 1988 The dynamics and structure of double-diffusive layers in sidewallheating experiments. J. Fluid Mech. 196, 135156.Google Scholar
Tanny, J. & Tsinober, A. B. 1989 On the behaviour of a system of double diffusive layers during its evolution. Phys. Fluids A 1, 606609.Google Scholar
Thangam, S., Zebib, A. & Chen, C. F. 1981 Transition from shear to sideways diffusive instability in a vertical slot. J. Fluid Mech. 112, 151160.Google Scholar
Thorpe, S. A., Hutt, P. K. & Soulsby, R. 1969 The effects of horizontal gradients on thermohaline convection. J. Fluid Mech. 38, 375400.Google Scholar
Toole, J. M. & Georgi, D. T. 1981 On the dynamics and effects of double-diffusively driven intrusions. Prog. Oceanogr. 10, 123145.Google Scholar
Tsitverblit, N. & Kit, E. 1993 The multiplicity of steady flows in confined double-diffusive convection with lateral heating. Phys. Fluids A 5, 10621064.Google Scholar
Walsh, D. & Ruddick, B. R. 1995 Double-diffusive interleaving: the influence of non-constant diffusivities. J. Phys. Oceanogr. 25, 348358.Google Scholar
Worthem, S., Mollo-Christensen, E. & Ostapoff, F. 1983 Effects of rotation and shear on doubly diffusive instability. J. Fluid Mech. 133, 297319.Google Scholar
Yoshida, J., Nagashima, H. & Niino, H. 1989 The behaviour of double-diffusive intrusions in a rotating system. J. Geophys. Res. 94, 42934937.Google Scholar