skip to content

Reactive-infiltration instabilities in fractures and porous rock

Tuesday 21st August 2012 - 11:30 to 12:30
INI Seminar Room 1
A reactive fluid flowing through a porous or fractured rock and dissolving the rock matrix may trigger an instability, leading to spontaneous formation of pronounced channels or wormholes. I will present a linear-stability analysis of this system and show that there are two different instabilites. One is associated with an initial uniform-porosity state and the other with a steadily propagating one-dimensional dissolution front. I will discuss the origin of both instabilities and the physical conditions under which they can be observed. In particular, it is argued that the former 'initial- state' instability is relevant to the dissolution of fractures in carbonate rocks, giving rise to the formation of limestone caves. Finally, I will discuss the later stages of the system evolution, when the channels interact, competing for the available flow; eventually the growth of the shorter ones ceases. This leads to self-similar patterns of growth, with the flow becoming concentrated within a few active channels.
The video for this talk should appear here if JavaScript is enabled.
If it doesn't, something may have gone wrong with our embedded player.
We'll get it fixed as soon as possible.
University of Cambridge Research Councils UK
    Clay Mathematics Institute London Mathematical Society NM Rothschild and Sons