CFD simulation of hydrodynamics of bubbly flow in bubble column

Abstract

Computational Fluid Dynamics (CFD) simulation is highly helpful for the study of large bubble column hydrodynamics because a validated model of a small reactor can be easily scaled up. Until recently CFD had not been used to study nozzle diameter effect on the hydrodynamics in bubble column. So, an attempt is made to simulate the flow pattern numerically so that scaling of numerical model can be done easily without depending on experiments. This research demonstrates the numerical simulation for bubble column using standard k-ε turbulence model. The problem is solved using Algebraic Slip Mixture Model (ASMM). The ASMM model solves conservation equations for only mixture rather than considering equations for both the phases individually. The simulation allows us to determine gas holdup, a key variable that need to be maximized to have a high reaction rates. A computer simulation of gas holdup is a complicated problem because the flow is generally turbulent and it requires tracking the transient movement of each bubble. The simulation predicts the flow pattern with different nozzle diameters and the use of sparger. The flow pattern was observed in simulations by considering physics of the problem. © Medwell Journals, 2011.