Hostname: page-component-7b7567c8c-2n9c9 Total loading time: 0 Render date: 2026-11-14T16:31:23.586Z Has data issue: false hasContentIssue false
  • English
  • Français

Experiments on the dynamics of a gravity current head

Published online by Cambridge University Press:  19 April 2006

R. E. Britter and
J. E. Simpson
R. E. Britter
Affiliation:
Department of Applied Mathematics and Theoretical Physics, University of Cambridge
J. E. Simpson
Affiliation:
Department of Applied Mathematics and Theoretical Physics, University of Cambridge
Get accessRights & Permissions [Opens in a new window]

Abstract

Some of the dense fluid at the front of an advancing gravity current is observed to be mixed with the ambient fluid. This process continues when the cross-stream non-uniformities at the head of the current are suppressed by advancing the floor beneath the head. In the resulting two-dimensional flow regular billows are visible. This paper considers experimentally and analytically the inviscid gravity current head and specifically includes the observed mixing at the head. Experimental results were obtained with an apparatus in which the head of the gravity current was brought to rest by an opposing uniform flow. The mixing appears to occur through Kelvin-Helmholtz billows generated on the front of the head and controls the dynamics of the head. A momentum balance is used to analyse the flow and the problem is closed by quantitatively introducing the billow structure.

Information

Type
Research Article
Information
Journal of Fluid Mechanics , Volume 88 , Issue 2 , 27 September 1978, pp. 223 - 240
Copyright
© 1978 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.)

Article purchase

Temporarily unavailable

References

Allen, J. R. L. 1971 Mixing at turbidity current heads, and its geological implications. J. Sediment. Petrol. 41, 97–113.Google Scholar
Barr, D. I. H. 1967 Densimetric exchange flow in rectangular channels. III. Large scale experiments. Houille Blanche 22, 619–631.Google Scholar
Benjamin, T. B. 1968 Gravity currents and related phenomena. J. Fluid Mech. 31, 209–248.Google Scholar
Brown, G. J. & Roshko, A. 1974 On density effects and large structure in turbulent mixing layers. J. Fluid Mech. 64, 775–816.Google Scholar
Farmer, H. G. 1951 An experimental study of salt wedges. Woods Hole Oceanographic Inst. Rep. no. 51–99.Google Scholar
Kármán, T. Von 1940 The engineer grapples with non-linear problems. Bull. Am. Math. Soc. 46, 615–683.Google Scholar
Keulegan, G. H. 1957 Form characteristics of arrested saline wedges. U.S. Nat. Bur. Stand. Rep. no. 5482.Google Scholar
Keulegan, G. H. 1958 The motion of saline fronts in still water. U.S. Nat. Bur. Stand. Rep. no. 5831.Google Scholar
Riddell, J. C. 1970 Densimetric exchange flow in rectangular channels. IV. Arrested saline wedge. Houille Blanche 25, 317–330.Google Scholar
Simpson, J. E. 1969 A comparison between laboratory and atmospheric density currents. Quart. J. Roy. Met. Soc. 95, 758–765.Google Scholar
Simpson, J. E. 1972 Effects of the lower boundary on the head of a gravity current. J. Fluid Mech. 53, 759–768.Google Scholar
Thorpe, S. A. 1973 Experiments on instability and turbulence in a stratified shear flow. J. Fluid Mech. 61, 731–751.Google Scholar
Yih, C.-S. 1965 Dynamics of Non-homogeneous Fluids, p. 137. Macmillan.