Radiation Conductivity for a Random Void-Solid Medium with Diffusely Reflecting Surfaces

Wolf, Jeffrey R. Tseng, Josefina W.C. Strieder, William.

Radiation Conductivity for a Random Void-Solid Medium with Diffusely Reflecting Surfaces - 725-734 p.

A variational principle is formulated for radiant heat transfer through the void spaces and conduction in the solid, of an arbitrary void-solid system with diffusely reflecting surfaces. Variational upper bounds on the effective conductivity of a void-solid suspension are expressed in terms of certain averages characterizing the random geometry. A radiation conductivity upper bound, calculated for a model porous medium generated by randomly placed, overlapping spheres, is compared with well-known results from kinetic theory and radiant heat transport. The variational principle provides a means to obtain useful estimates and upper bounds on the thermal radiation conductivity, that include multiple and anisotropic diffusive scattering in a bed of large particles.

0017-9310


Radiation Conductivity
Random Void
Solid Medium
Diffusely Reflecting Surfaces