Spectral radiative properties of micro-scaled structure inner alumina ligament in open cell foam

Accurately predicting the radiative properties of micro-scaled structure inner ligament is of primary importance for the analysis of radiative transfer in ceramic open cell foams. In this work, a numerical method for predicting the spectral radiative properties of alumina ligament medium with micro scaled structure considered is introduced. Firstly, the closely packed random structure modeled with the Discrete Element Method is applied for reconstructing the micron structure inner alumina ligament with real morphology characteristics considered. Furthermore, the spectral radiative properties of modeled closely packed structures are predicted numerically with the Finite-Difference Time-Domain method in the waveband of near infrared light, meanwhile the equivalent volumetric radiative properties of modeled micron structures are retrieved using the Adaptive Particle Swarm Optimization method. As observed, the reflectivity and transmissivity of modeled closely packed structure inner alumina ligament show opposite radiative behaviors and are strongly influenced by increasing thickness, while the absorptivity is usually small and hardly affected. Additionally, the equivalent absorption coefficient of ligament structure is usually small. However, the equivalent scattering coefficient of micron structure inner ligament is enhanced obviously and shows strong spectral selectivity due to the structural characteristics.