Analysis on influences of micro-scale ligament morphology and pore-level structure parameter on spectral properties of alumina foam

Abstract

The radiative behaviors occurring inside ceramic alumina foams are influenced by the multi-scale structures ranging from micro-scale to pore-level, which determine the equivalent radiative properties. In this work, the microscopic morphologies of ligament and pore-level porous structure of alumina foam are introduced, while the spectral apparent and volumetric radiative parameters are predicted by performing a trans-scale simulation coupling the FDTD method with the Monte Carlo ray tracing method. By applying different simplified models at different scales and reconstructed realistic structure models respectively, the corresponding spectral radiative parameters of alumina foam sheets are compared and discussed, with different microscopic morphology characteristics and pore-level structure parameters considered. By comprehensive analysis, it can be observed that the spectral radiative properties of alumina foam are affected by complex multi-scale structural characteristics. The pore-level parameters have great influences on the apparent spectral radiative properties and equivalent extinction coefficient, while the micro-scale ligament structures change the spectral selectivity and scattering asymmetry factor obviously. For the scattering albedo, the effects produced by various micro-scale and pore-level structural parameters are close.