Numerical investigation of gas-liquid flow hydrodynamics in three-dimensional bottom-blown reactor via LES-VOF coupled model

Abstract

In this study, a coupled interface-resolved volume of fluid model and large eddy simulation is employed to explore bubble dynamics in a three-dimensional bottom-blown reactor. After the model validation, the bubble plume area, motion characteristics, and force analysis are analyzed. Three distinct stages of bubble rising are quantitatively identified: disengaging nozzle stage, accelerated ascent stage, and stable upward stage. Specifically, an increase in reactor height reduces both the bubble rising velocity and interphase surface tension impact. Moreover, the influence of inlet size on bubble volume frequency distribution surpasses that of gas injection velocity. The gas penetration depth remains relatively unchanged amidst variations in boundary conditions, while the liquid type profoundly influences it. Axial fluid velocity, dynamic pressure, Reynolds number, and turbulent viscosity peak at the reactor center. Liquid back-mixing is found near the bottom blowing wall region, coupled with an enhanced distribution of turbulent viscosity.