The effective radiative conductivity of fibrous material is an important part of the evaluation of the thermal performance of fibrous insulators. To better evaluate this material property, a three-dimensional direct simulation model which calculates the effective radiative conductivity of fibrous material is proposed. The simplified model assumes that the fibers are in a cylindrical shape and does not require identically-sized fibers or a symmetric configuration. Using a geometry with properties resembling those of a fibrous insulator, a numerical calculation of the geometric configuration factor is carried out. The results show the dependency of thermal conductivity on temperature as well as the orientation of the fibers. The calculated conductivity values are also used in the continuum heat equation, and the results are compared to the ones obtained using the direct simulation approach, showing a good agreement.
|Number of pages
|International Journal of Heat and Mass Transfer
|Published - Apr 2015
Bibliographical noteFunding Information:
The authors gratefully acknowledge the support of B. Plaster regarding the development of this work. They are also beholden to K. Tagavi for several useful discussions, as well as A. Kucharski, Jr. and D. Smith for carefully reading the manuscript. Additional financial support for this work was provided by Kentucky EPSCoR and NASA RA award NNX13AN04A.
© 2014 Elsevier Ltd.
- Anisotropic conductivity
- Effective conductivity
- Fibrous geometry
- Radiative heat transfer
ASJC Scopus subject areas
- Condensed Matter Physics
- Mechanical Engineering
- Fluid Flow and Transfer Processes