Energy Balances for Axisymmetric Gravity Currents in Homogeneous and Linearly Stratified Ambients

Ungarish, M. and Huppert, H. E. (2008) Energy Balances for Axisymmetric Gravity Currents in Homogeneous and Linearly Stratified Ambients. Journal of Fluid Mechanics, 616 (-1). pp. 303-326. DOI https://doi.org/10.1017/S002211200800400X

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Abstract

We analyse the exchange of energy for an axisymmetric gravity current, released instantaneously from a lock, propagating over a horizontal boundary at high Reynolds number. The study is relevant to flow in either a wedge or a full circular geometry. Attention is focused on effects due to a linear stratification in the ambient. The investigation uses both a one-layer shallow-water model and Navier–Stokes finite-difference simulations. There is fair agreement between these two approaches for the energy changes of the dense fluid (the current). The stratification enhances the accumulation of potential energy in the ambient and reduces the energy decay (dissipation) of the two-fluid system. The total energy of the axisymmetric current decays considerably faster with distance of propagation than for the two-dimensional counterpart.

Item Type:	Article
Uncontrolled Keywords:	08AREP; IA57; DAMPT;
Subjects:	02 - Geodynamics, Geophysics and Tectonics
Divisions:	02 - Geodynamics, Geophysics and Tectonics
Journal or Publication Title:	Journal of Fluid Mechanics
Volume:	616
Page Range:	pp. 303-326
Identification Number:	https://doi.org/10.1017/S002211200800400X
Depositing User:	Sarah Humbert
Date Deposited:	04 Jun 2009 16:16
Last Modified:	23 Jul 2013 09:55
URI:	http://eprints.esc.cam.ac.uk/id/eprint/1072

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