Radiative behavior of low-porosity ceramics: II–Experimental and numerical study of porous alumina up to high temperatures

•Infrared radiative behavior of 22% porous alumina disks are measured and simulated.•Reflectance and transmittance measured at 25 ∘C, emittance measured up to 1300 ∘C.•Radiative properties determined from microstructure via physical-optics-based model.•RTE resolved for reflectance, transmittance, and emittance up to high temperatures.•Good agreement between measurements and simulations validate novel multi-scale model.