Real particle model (RPM) and porous media model (PMM) have been taken out in the present study to investigates numerically the mixing of an axial flow with a cross flow in a structured packed bed. Three-dimensional computational fluid dynamics CFD simulations have been carried out corresponding to the experimental setup. ANSYS 14 was used for CFD simulation with standard κ–ε turbulence model. The study focus on the effect of the contact point treatment for the particles within the packed bed. Three configuration layout of particles packing are used; gap, overlap and bridge to avoid a high skewed element in the vicinity of contact region. A body center cubic (BCC) packing with spherical particles of 52 mm diameter was used with porosity of 0.35. The mixing is introduced by side injection of nitrogen to a box with a structured bed of 984 spheres with an axial air flow under different operating conditions. Parametric variables are; volume flow rate ratio, flow conditions and injection position. It is shown that the CFD simulation for (RPM) results can predict the cross flow mixing reasonably. The study revealed that the gap configuration layout in a RPM can best fit the experimental data. However, the overlap method results are much fit with the PMM results but there is a significant deviation from the experimental data. In addition, the PMM with porosity 0.7 is fitted well with the RPM of porosity 0.35. |
