Hostname: page-component-848d4c4894-pjpqr Total loading time: 0 Render date: 2024-06-16T21:32:54.945Z Has data issue: false hasContentIssue false

Boundary-layer separation of a two-layer rotating flow on a β-plane

Published online by Cambridge University Press:  21 April 2006

Lee-Or Merkine
Affiliation:
Department of Mathematics, Technion-Israel Institute of Technology, Haifa 32000, Israel
Leonid Brevdo
Affiliation:
Geophysical Fluid Dynamics Laboratory/NOAA, Princeton University, Princeton, NJ 08540, USA

Abstract

The problem of quasi-geostrophic two-layer flow past a vertical cylinder on a β-plane is investigated analytically and numerically. Two parameter regimes are considered: (i) 0 ≤ E½/ε ≤ ∞ and β = O(1); (ii) E½/ε [Gt ] 1 and βε/E½ = O(1). ε is the Rossby number, E is the Ekman number and β is the beta parameter. In the first parameter regime the nonlinear interior and boundary-layer equations are integrated to determine if and when the wall shear stress vanishes so that an estimate of the condition for separation in the classical sense can be obtained. The results seem to explain the enhancement/suppression of separation in retrograde/prograde flows and the east-west asymmetry observed in the experiments of Boyer & Davies (1982). In the second parameter regime the analysis is linear and the vorticity balance is dominated by the β-effect and Ekman suction. When the flow at infinity is vertically sheared, two large standing interior eddies can be generated next to the cylinder. Only the interior solutions are given in (ii) since the boundary-layer flow is irrelevant to the large-scale behaviour.

Type
Research Article
Copyright
© 1986 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

Abramowitz, M. & Stegun, I. A. 1970 Handbook of Mathematical Functions, Dover.
Barcilon, V. 1970 Phys. Fluids 13, 537544.
Boyer, D. L. 1970 Trans. ASME D: J. Basic Engng 92, 430436.
Boyer, D. L. & Davies, P. A. 1982 Phil. Trans. R. Soc. Lond. A 306, 533556.
Brevdo, L. 1983 Separation of boundary layers in a two strata flow in a rotating fluid. Ph.D. thesis, Technion - Israel Institute of Technology, Haifa.
Brevdo, L. & Merkine, L. 1985 Proc. R. Soc. Lond. A 400, 7595.
Goldstein, S. 1948 Q. J. Mech. Appl. Maths. 1, 4369.
Greenspan, H. P. 1968 The Theory of Rotating Fluids Cambridge University Press.
Hart, J. E. 1972 Geophys. Fluid Dyn. 3, 181209.
Hogg, N. G. 1972 Geophys. Fluid Dyn. 4, 5181.
Hogg, N. G. 1980 In Orographic Effects in Planetary Flows (ed. R. Hide & P. H. White), pp. 167-205 G.A.R.P. Publication Series, No. 23 Geneva: World Meteorological Organization.
Mccartney, M. S. 1975 J. Fluid Mech. 68, 7195.
Merkine, L. 1980 J. Fluid Mech. 99, 399409.
Merkine, L. 1985 J. Fluid Mech. 157, 501518.
Merkine, L. & Solan, A. 1979 J. Fluid Mech. 92, 381392.
Miles, J. W. 1968 J. Fluid Mech. 33, 803814.
Page, M. A. 1982 J. Fluid Mech. 123, 303313.
Pedlosky, J. 1979 Geophysical Fluid Dynamics. Springer.
Rosenhead, L. 1963 Laminar Boundary Layers. Oxford University Press.
Smith, F. T. 1982 IMA J. Appl. Maths. 28, 207281.
Stommel, H. 1948 Trans. Am. Geophys. Union 99, 202206.
Vaziri, A. & Boyer, D. L. 1971 J. Fluid Mech. 50, 7995.
Walker, J. D. & Stewartson, K. 1972 Z. angew Math. Phys. 23, 745752.
White, W. B. 1971 J. Phys. Oceanogr. 1, 161168.