Dynamic mesh simulation on the effect of sloshing on concurrent two-phase flow fields for two-dimensionally packed columns simulations

Abstract

Optimisation design of gas-liquid packed column filled with structured packing during the absorption process requires an accurate prediction of the liquid distribution. A two-dimensional computational fluid dynamics (CFD) model is developed for the structured packed column which is applied in floating liquefied natural gas (FLNG) in offshore platforms. And several user-defined functions (UDFs) based on the dynamic mesh technology are incorporated in Fluent to quantitatively evaluate how the pressure drops, the liquid volume fraction, and liquid radial and axial velocities are affected by sloshing angles, periods, and displacements. The results show that the sloshing angle has significant effects on the liquid volume fraction in the central region of the column as its value increases by 145% for a sloshing angle of 9°. And the turning points of the liquid volume fraction and liquid radial velocity appear at the same time. Furthermore, the liquid volume fraction, the liquid radial and axial velocities of the packed column fluctuate periodically around the values of the vertical steady state under different sloshing periods and displacements. The critical value of the sloshing displacement is determined as 150 mm based on the minimum range of liquid radial dispersion in the packed column.