Calculation of the Thermal Conductivity and Gas Permeability in a Uniaxial Bundle of Fibers

Authors

  • Daniel J. Skamser,

    1. Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208-3108
    2. National Institute of Standards and Technology, Building Materials Division, Gaithersburg, Maryland 20899
    3. Master Builders Technology, Cleveland, Ohio 44122
    4. Illinois Superconductor Corporation, Evanston, Illinois 60201
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    • *

      Member, American Ceramic Society.

    • Northwestern University.

  • Dale P. Bentz,

    1. Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208-3108
    2. National Institute of Standards and Technology, Building Materials Division, Gaithersburg, Maryland 20899
    3. Master Builders Technology, Cleveland, Ohio 44122
    4. Illinois Superconductor Corporation, Evanston, Illinois 60201
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    • *

      Member, American Ceramic Society.

    • National Institute of Standards and Technology.

  • R. Tate Coverdale,

    1. Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208-3108
    2. National Institute of Standards and Technology, Building Materials Division, Gaithersburg, Maryland 20899
    3. Master Builders Technology, Cleveland, Ohio 44122
    4. Illinois Superconductor Corporation, Evanston, Illinois 60201
    Search for more papers by this author
    • *

      Member, American Ceramic Society.

    • §

      Master Builders Technology.

  • Mark S. Spotz,

    1. Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208-3108
    2. National Institute of Standards and Technology, Building Materials Division, Gaithersburg, Maryland 20899
    3. Master Builders Technology, Cleveland, Ohio 44122
    4. Illinois Superconductor Corporation, Evanston, Illinois 60201
    Search for more papers by this author
    • *

      Member, American Ceramic Society.

    • Illinois Superconductor Corporation.

  • Nick Martys,

    1. Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208-3108
    2. National Institute of Standards and Technology, Building Materials Division, Gaithersburg, Maryland 20899
    3. Master Builders Technology, Cleveland, Ohio 44122
    4. Illinois Superconductor Corporation, Evanston, Illinois 60201
    Search for more papers by this author
    • National Institute of Standards and Technology.

  • Hamlin Jennings,

    1. Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208-3108
    2. National Institute of Standards and Technology, Building Materials Division, Gaithersburg, Maryland 20899
    3. Master Builders Technology, Cleveland, Ohio 44122
    4. Illinois Superconductor Corporation, Evanston, Illinois 60201
    Search for more papers by this author
    • *

      Member, American Ceramic Society.

    • Northwestern University.

  • D. Lynn Johnson

    1. Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208-3108
    2. National Institute of Standards and Technology, Building Materials Division, Gaithersburg, Maryland 20899
    3. Master Builders Technology, Cleveland, Ohio 44122
    4. Illinois Superconductor Corporation, Evanston, Illinois 60201
    Search for more papers by this author
    • *

      Member, American Ceramic Society.

    • Northwestern University.


  • T. M. Besmann—contributing editor

  • Presented at the 95th Annual Meeting of the American Ceramic Society, Cincinnati, OH, April 20, 1993 (Basic Science Division, Paper No. SIV-20-93).

  • Supported by DARPA/ONR Grant No. N00014-90-J-4020

Abstract

A model of the local microstructure of a bundle of fibers is simulated and used as the basis for calculations of transport properties. This, in turn, can be used in a macroscopic model of the chemical vapor infiltration process. An expanding/overlapping circle representation of the micro-structure simulates the deposition of matrix in a uniaxial bundle of fibers. An iterative heat conduction algorithm is used to calculate the transverse thermal conductivity based on the thermal conductivities of the solid and gas phases. The permeability of gas through the microstructure is calculated for flow both parallel and transverse to overlapping cylinders using a Stokes equation and assuming a Darcy's law behavior. Both the simulations of the microstructure and associated calculations of the transport properties compare favorably with experimental data. Darcy's law for the behavior of gas in a bundle of fibers is shown to be valid for gas pressures of 5–13 kPa.

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