Effects of local non-uniform particle temperature on radiative heat transfer in particulate systems

In many high-temperature particulate systems, the temperature differences between particles in some local sites are often large. Due to the nonlinear nature of the Stefan-Boltzmann law, the average radiative source term deviates significantly from the radiative source term based on the average particle temperature. In this paper, a Gaussian probability density function is used to simulate the distribution of particle temperature. The discrete ordinates method is selected to solve the radiative heat transfer in particulate systems and the axial radiative heat flux is calculated. The results show that, when the non-uniform degree of local particle temperature is large, calculating the radiative source term by local average particle temperature will result in large errors in the calculation of radiative heat transfer, especially in the absorption-dominated case.