Numerical analysis model for thermal conductivities of packed beds with high solid-to-gas conductivity ratio

A new numerical analysis model is proposed for the effective thermal conductivity of a packed bed of solid particles in static gas. The thermal conductivity of bulk region is calculated by multiplying thermal conductivity of a conventional cubic unit cell model and an effective contact number estimated to be 2.06 for a randomly distributed packed bed. Near the wall, thermal conductivity is analyzed with a model containing a container wall that has the effect of decreasing it. The calculated ratio of thermal conductivity between near wall and bulk is compared with those from literature and the physical meaning of the ratio is studied.