COMBINING MICRO- MESO- AND MACRO-SCOPIC NUMERICAL METHODS FOR MULTISCALE RADIATIVE TRANSFER MODELING OF SiC-BASED FOAMS UP TO VERY HIGH TEMPERATURES

Abstract

A general multiscale numerical approach is proposed to finely reproduce, up to 1300 K, the radiative heat transfers within alpha silicon carbide-based open-cell foams, with tuned chemical and textural features. The complete modeling is based on a thorough analysis performed at micro-, meso-, and macro-scopic scales. To gauge, at the microscopic scale, the influence of the electron-phonon coupling on the intrinsic optical properties of silicon carbide, a molecular dynamic method involving a modified Tersoff potential is used. Then, at the mesoscopic scale, with optical indices provided by our molecular dynamic simulations, a collision-based Monte Carlo ray tracing method is used for retrieving the homogenized radiative properties of the selected foams. Finally, at the macroscopic scale, for a set of foams (porosity ∼ 0.4-0.9), we used our micro-meso constructed radiative properties for calculating the propagation of radiation by solving the radiative transfer equation using the vectorial finite element method. In addition, a fictitious foam constructed using heavily chemical doping at microscopic level, is put forward to change the volumetric propagation of the thermal radiation.