The front condition for intrusive gravity currents

A mathematical model is developed for a high Reynolds number, quasi-steady, intrusive gravity current propagating into a two-layer ambient fluid. The model is based on inviscid, irrotational flow theory, and is used to predict the rate of advance of the current front as a function of its head height...

Full description

Saved in:
Bibliographic Details
Published in:Journal of hydraulic research 2008-11, Vol.46 (6), p.788-801
Main Authors: Nokes, Roger I., Davidson, Mark J., Stepien, Charlotte A., Veale, William B., Oliver, Rowan L.
Format: Article
Language:English
Subjects:
Earth sciences
Earth, ocean, space
Exact sciences and technology
Front condition
gravity current
Hydrology. Hydrogeology
intrusion
inviscid irrotational flow
lock exchange
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:A mathematical model is developed for a high Reynolds number, quasi-steady, intrusive gravity current propagating into a two-layer ambient fluid. The model is based on inviscid, irrotational flow theory, and is used to predict the rate of advance of the current front as a function of its head height. The key underlying assumptions of the model are that the local conditions at the head determine its speed of propagation, and that the upstream portion of the head is well approximated by an inviscid, irrotational flow. In order to provide a complete set of boundary conditions it is assumed that the ambient flow over the top of the head is horizontal, but not uniform. An upper bound solution is derived and is compared with a full solution generated with an optimisation based Boundary Element Method technique. The upper bound solution is shown to be entirely adequate for relative current heights greater than 0.3. The results from two experimental programmes provide support for the model predictions, and particle tracking velocimetry measurements indicate that the assumption of horizontal flow over the head is reasonable.
ISSN:0022-1686
1814-2079
DOI:10.1080/00221686.2008.9521923