3D CFD simulation of turbulent flow distribution and pressure drop in a dividing manifold system using openfoam

Abstract

The flow distribution in a manifold system is a critical design parameter which affects the performance of majority of the chemical equipment. The flow mal-distribution may lead to serious issues such as (i) reduced heat or mass transfer (ii) enhanced pressure drop (iii) high energy dissipation and (iv) creation of dead zones or hot spots. The objective of the present investigation is to identify potential design strategies for attaining uniform fluid flow, reduced pressure drops and minimum energy dissipation inside dividing manifold system. 3D CFD simulations using OpenFoam have been performed to study the effect of eight different design strategies on the extent of non-uniformity (ENU) and pressure drop inside manifold system. The results reveal the dominance of momentum effect near the inlet which results in reverse flow through the branched tubes near the inlet whereas maximum discharge occurs through the tubes near the closed end. The turbulent kinetic energy (k) and dissipation rate (ε) are very high near the T junction, decreases as the flow precedes in the downstream direction and vanishes completely near the closed end of manifold. This study for the very first time reveals the roles of turbulent parameters (k and ε) in controlling the flow mal-distribution and pressure drop inside manifold systems. The most effective design strategies for achieving maximum flow uniformity and minimum energy dissipation are (i) inclusion of perforated baffle which reduces the vortex formation and results in 95% reduction in ENU¯ and (ii) converging header which results in 66% reduction in ENU¯.