Modeling of granular packed beds, their statistical analyses and evaluation of effective thermal conductivity

Thermal conductivity of packed beds plays the key role in the emerging technologies of selective laser melting/sintering. The objective is to study the influence of the packed bed structure on the contact thermal conductivity. The discrete (network) model of the contact thermal conductivity in the packed particle layer is proposed. The task of heat transfer due to the contact thermal conductivity of the system of parallel the located cylinders with the fixed thermal resistance of the contact is solved in the 2D case. The 3D-task on the heat transfer through the layer of spherical particles of finite thickness in between heated solid massive bodies with constant and different temperatures is solved. In the calculations, the package structures were varied: the regular (with the cubic symmetry), random (with the mono- and poly-disperse particles), as well as the porosity and mean coordination number. The effective thermal conductivity coefficient was evaluated as the packed bed structure, the mean porosity, and coordination number were varied. The calculation results agree with the known analytical solutions. The statistical analysis of regular and packed beds of solid spheres is presented.