Numerical investigation on the flow and heat transfer of a multi-lobe particle and equivalent spherical particles in a packed bed with considering the wall effects

Abstract

In this paper, wall effects on cross and axial flow and heat transfer of a multi-lobe particle in a packed bed was investigated numerically. In numerical analysis, finite element method was used for solving partial equations. Effect of bends and turns in flow path, heat transfer for equivalent spherical particles arranged in tandem, effect of wall proximity on the heat transfer for a tri-lobe and the effect of wall on the particle Nusselt number were investigated. The results show that the Nusselt number obtained for cross flow is greater than that obtained for the axial flow and increasing the length-to-diameter ratio changes parameters such as the flow cross section, the area-to-volume ratio, and the effect of bed wall on the particle. Moreover, heat transfer improves as the particle moves closer to the wall and the Nusselt number increases. Also, increasing the number of particles led to a corresponding increase in heat transfer at constant flow rate.