Diffusion in an absorbing porous medium : from microscopic geometry to macroscopic transport
Author(s)Forney, David C., III
Massachusetts Institute of Technology. Dept. of Mechanical Engineering.
Daniel H. Rothman.
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Two physical models of diffusion in absorbing porous media are proposed on two length scales. One models diffusion in the pore space of a random medium with absorbing interfaces while the other is a reaction diffusion model where particles are absorbed in the bulk. Typical particle traveling distances and a bulk absorption coefficient are described in terms of general geometrical characteristics of a random medium and the analytical relations are found to compare well with numerical experiments. For the case of geometries consisting of randomly placed cubes, absorption in the bulk scales with the solid fraction to the two-thirds power. The statistical distribution of reaction rates in these models is found to be inversely related to the reaction rate. A quasi-static Monte-Carlo model is also investigated. The more complex problem of microbial extracellular enzyme distributions in marine sediment was an inspiration for this work.
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2007.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.Includes bibliographical references (p. 71-73).
DepartmentMassachusetts Institute of Technology. Dept. of Mechanical Engineering.
Massachusetts Institute of Technology