Hostname: page-component-78c5997874-j824f Total loading time: 0 Render date: 2024-11-17T13:21:35.659Z Has data issue: false hasContentIssue false

On the slow motion of a spheroid in a rotating stratified fluid

Published online by Cambridge University Press:  04 November 2016

E. R. Johnson*
Affiliation:
Department of Mathematics, University College London, London WC1E 6BT, UK
Stefan G. Llewellyn Smith
Affiliation:
Department of Mechanical and Aerospace Engineering, Jacobs School of Engineering, UCSD, La Jolla, CA 92093-0411, USA
*
Email address for correspondence: [email protected]

Abstract

We consider the slow motion generated when a body is set into motion relative to an incompressible, inviscid, non-diffusive rotating stratified fluid, showing that there is generated in general a topographic Rossby wave which leads to non-decaying fluctuations in the lift on the obstacle and a fluctuating non-zero drag. The problem is relevant to the flow patterns and forces excited when slow oceanic flows cross bottom topography, and suggests a mechanism for slow fluctuations observed in laboratory experiments.

Type
Rapids
Copyright
© 2016 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

Cheng, H. K. & Johnson, E. R. 1982 Inertial waves above an obstacle in an unbounded, rapidly rotating fluid. Proc. R. Soc. Lond. A 383, 7187.Google Scholar
Drazin, P. G. 1961 On the steady flow of a fluid of variable density past an obstacle. Tellus 13, 239251.Google Scholar
Grimshaw, R. 1969 Slow time-dependent motion of a hemisphere in a stratified fluid. Mathematika 16, 231248.Google Scholar
Hide, R., Ibbetson, A. & Lighthill, M. J. 1968 On slow transverse flow past obstacles in a rapidly rotating fluid. J. Fluid Mech. 32, 251272.Google Scholar
d’Hieres, G. C., Davies, P. A. & Didelle, H. 1990 Experimental studies of lift and drag forces upon cylindrical obstacles in homogeneous, rapidly rotating fluids. Dyn. Atmos. Oceans 15, 87116.Google Scholar
Huppert, H. E. & Bryan, K. 1976 Topographically generated eddies. Deep-Sea Res. 23, 655679.Google Scholar
James, I. N. 1980 The forces due to geostrophic flow over shallow topography. Geophys. Astrophys. Fluid Dyn. 14, 225250.Google Scholar
Johnson, E. R. 1982 The effects of obstacle shape and viscosity in deep rotating flow over finite-height topography. J. Fluid Mech. 120, 359383.Google Scholar
Johnson, E. R. 1984 Starting flow for an obstacle moving transversely in a rapidly rotating fluid. J. Fluid Mech. 149, 7188.Google Scholar
Lighthill, M. J. 1965 Group velocity. J. Inst. Maths Applics. 1, 128.Google Scholar
Llewellyn Smith, S. G. 2000 The asymptotic behaviour of Ramanujan’s integral and its application to two-dimensional diffusion-like equations. Eur. J. Appl. Maths 11, 1328.Google Scholar
Mason, P. 1977 Forces on spheres moving horizontally in a rotating stratified fluid. Geophys. Astrophys. Fluid Dyn. 8, 137154.Google Scholar
Morse, P. M. & Feshbach, H. 1953 Methods of Theoretical Physics. McGraw-Hill.Google Scholar
Stewartson, K. 1953 On the slow motion of an ellipsoid in a rotating fluid. Q. J. Mech. Appl. Maths 6, 141162.Google Scholar
Stewartson, K. 1967 On slow transverse motion of a sphere through a rotating fluid. J. Fluid Mech. 30, 357369.Google Scholar
Taylor, G. I. 1923 Experiments on the motion of solid bodies in rotating fluids. Proc. R. Soc. Lond. A 104, 213218.Google Scholar