Experimental characterization of Al2O3 foam based on high temperature thermal response experiments

Abstract

Alumina foam has potential application value in aerospace, solar energy, and other fields. This study proposes a combined radiative-conductive heat transfer model, in which the thermal conductivity and extinction coefficient are temperature-dependent, and the radiation transfer equation is solved by the Monte Carlo method. A self-designed setup is used to measure the high temperature thermal response experiments of alumina foams in 10PPI, 20PPI, and 40PPI. Combined with the genetic algorithm, the thermal conductivity, extinction coefficient, albedo and asymmetry factor of scattering are solved. According to the inversion results, the extinction coefficient of materials with a high pore density is more sensitive to temperature than those with a lower pore density. The thermal conductivity of high pore density materials is greater than that of low pore density materials. The thermal conductivity and extinction coefficient slightly remain basically unchanged as atmospheric pressure increases.