Prediction of cross flow mixing in the structured packed bed through CFD simulation using (FBM and PMM) and validation with experiments

Abstract

This study focuses on prediction of cross flow mixing in structured bed by using O2 molar concentration through CFD simulation. The mixing of the axial flow with cross flow in structured bed have been studied experimentally in a test box. The test box containing a 924 spherical particles of 52 mm diameter were arranged to achieve the simple cubic configuration which leads to a porosity of 0.48. 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 k-ε turbulence model. Fixed bed model (FBM) and porous media model (PMM) are used in this numerical work. Three different methods of contact point treatment are considered to obtain results using FBM. Moreover, results obtained through FBM (gap method) and PMM were also compared. Cross flow mixing takes place between N2 entering via side injection and air entering at the bottom of the test box. Parametric variables are; lance diameter, lance position, and volume flow rate ratio. It is shown that results of CFD simulations using FBM can predict the cross flow mixing reasonably. The curves for O2 concentration obtained through PMM are shifted little bit away from curves of FBM. It is also interesting to note that results of FBM with gap method fit best with the experimentally data.

Keywords

• CFD
• cross flow mixing
• packed bed
• simple cubic
• contact point
• and porous medium