Determination of radiative properties of representative and real open cell foam structures using the finite volume method

In the present work, a numerical model is developed to determine radiative properties of a few idealized open cell structures, namely, Dul'nev's unit cell, Viskanta's unit cell and cubic unit cell. A parametric study is carried out to investigate the effect of porosity, pore density and surface reflectivity on radiative properties of the porous structures. The developed 3-D numerical model is also applied to estimate radiative properties of actual foam structures that are obtained using CT scan. The proposed model is based on the information of solid and fluid voxels and a Cartesian coordinate based blocked-off region approach integrated with the finite volume method is used to solve the radiative transfer equation. It is shown that the periodic boundary condition with a specular reflection approach applied to an unit cell can mimic a complete porous structure with multiple cells. The ranges of extinction coefficient and scattering albedo predicted using present numerical model fall within the expected limits.