Entropy-mediated structure-permeability relations in skeletal porous materials

Zeit:	24. Januar 2006, 16:00 – 17:30 Uhr
Referent*in:	Prof. Peter King, Department of Science and Engineering, Imperial College London, U.K
Veranstaltungsort:	Pfaffenwaldring 61, Raum U1.003 (MML), Universität Stuttgart
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The aim of this paper is to formulate a new framework for characterisation of porousmaterials and for obtaining first-principles structure-permeability relaions. Theformaslism is based on a representation of the porous medium in skeletal form and involvesseveral steps. First, the skeleton is characterised by a new fabric tensor that describesthe local pore structure. Second, the fabric tensor is used to construct a configurationalentropy of the porous medium, based on Edwards??? compactivity concept. Both the fabrictensor and the entropic analysis are initially illustrated in two-dimensions and are thenextended to three-dimensional systems. Third, the local pore-scale permeability is expressedin terms of the structure of the skeleton and the degrees of freedom that comprise the phasespace of configurational states. Fourth, the pore-scale permeability is calculated as anexpectation value over the partition function.We propose that the same procedure can be used to find the conductivity of the porous mediumwhen it is filled with brine water. This makes it possible to derive a theoretical relationbetween these two transport properties.