An unstructured lattice Boltzmann method for numerical simulation of radiative transfer in porous media

An unstructured lattice Boltzmann method for simulating radiative transfer in porous media at the pore scale is developed based on Chapman-Enskog analysis, Taylor expansion, and finite-volume discretization. The unstructured lattice Boltzmann method achieves an order of magnitude improvement in efficiency over the Monte Carlo method while maintaining comparable accuracy in two-dimensional benchmark cases. Utilizing the developed unstructured lattice Boltzmann method, the effects of skeleton surface emissivity, cross-sectional number, shape, and size on radiative transfer are investigated. Results reveal that skeleton emissivity significantly influences temperature and heat flux distribution, while cross-sectional geometry affects temperature uniformity, especially for structures with fewer pores. The findings underscore the importance of balancing key parameters for optimal thermal radiation performance in porous media. The unstructured lattice Boltzmann method presents a promising tool for advancing the understanding of radiative transfer in complex porous systems.