The paper reports results of an analysis concerning the infuence of a computational domain discretization method on the numerical stability of a model as well as the calculation error. The topology of a packed bed of a granular material consisting of granules contacting tan- gentially in one point makes the modeling of heat and mass transfer due to the fluid flow in such a domain a chalenging task. Therefore, the contribution of this paper constitutes a summary of discretization methods with discussion and guidelines allowing one to effectively select the most favourable method dedicated to discretization of the domain. The validation using Particle Image Velocimetry and evaluation of the impact of inflow velocity on the experimental and numerical research results are also presented in the paper.