Journal of Fluid Mechanics

Papers

Gravity currents over fractured substrates in a porous medium

DAVID PRITCHARDa1

a1 Department of Mathematics, University of Strathclyde, 26 Richmond Street, Glasgow G1 1XH, UK dtp@maths.strath.ac.uk

Abstract

We consider the behaviour of a gravity current in a porous medium when the horizontal surface along which it spreads is punctuated either by narrow fractures or by permeable regions of limited extent. We derive steady-state solutions for the current, and show that these form part of a long-time asymptotic description which may also include a self-similar ‘leakage current’ propagating beyond the fractured region with a length proportional to t1/2. We discuss the conditions under which a current can be completely trapped by a permeable region or a series of fractures.

(Received February 27 2006)

(Revised March 21 2007)

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