An investigation of the geometric influences on pore space diffusion

This paper investigates the characteristics of gas diffusion through a complex pore space in terms of its geometric features. Diffusion is simulated in 50 realizations of a 2-dimensional model where the solid phase is generated by a non-overlapping disk process. Principal component analysis of the flux at different time points shows that most of the variation is accounted for by the steady state flux and a delaying effect. It is shown that the first component, mainly determined by the steady state flux, can be successfully predicted (adjusted R-2 = 91%) by regarding the pore space as analogous to an electric circuit, and obtaining the current in this circuit. The influences on the delay are mon complex, and a regression model with 7 geometric measures achieves an adjusted R-2 of 76%. (C) 1999 Elsevier Science B.V. All rights reserved.