Tomography-based Monte Carlo determination of radiative properties of reticulate porous ceramics

A 3D digital representation of a reticulate porous ceramic (RPC) sample, generated by computer tomography (CT), is employed to determine its porosity, surface-to-volume ratio, and the minimum size of a representative elementary volume (REV) for continuum domain. Subsequently, the Monte Carlo (MC) ray-tracing technique is applied to calculate the extinction coefficient and scattering phase functions based on the probabilistic distribution functions of the extinction path-length and of the directional cosine of incident radiation. The methodology and governing equations are presented for diffusely and specularly reflecting surfaces. The isotropic assumption is justified by demonstrating that the extinction coefficient is directionally independent.