| Abstract: | The simulation of internal-loop airlift reactors is challenging because complex meso-scale structures exist in different sections of the reactor,separated by the draft tube.This paper reports on the computational fluid dynamics(CFD) simulation of internal-loop airlift reactors using a new drag model derived from the dual-bubble-size(DBS) model,an extended energy-minimization multi-scale(EMMS) approach for gas-liquid flows.Compared with the traditional Schiller-Naumann(S-N) correlation,the new model improves the simulation of gas holdup in the riser and downcomer significantly.In particular,gas holdup and circulation of two-phase flow can be modeled successfully using the new model,whereas traditional drag models such as the S-N correlation show an absence of gas in the downcomer.The simulation demonstrates the advantage and potential of this new model for internal-loop airlift reactors. |
