Numerical Simulation of the Interfacial Dynamics of Highly Viscous Fluid on a Single Packing Element by the Volume-of-Fluid Method

The dynamic characteristics of liquid with high viscosity impact on stagnant packing are investigated by a computational fluid dynamics (CFD) method. The three-dimensional model, employing the volume-of-fluid (VOF) approach, simulates the evolution of liquid profiles and describes four interaction stages—approaching, encapsulation, uncovering, and detachment—between the liquid and the packings, including Raschig rings, Pall rings, and Cascade mini rings. Based on the analysis of liquid dynamic behavior, the effects of packing type, packing size, and liquid viscosity on the liquid holding volume, film area, and surface renewal rate of highly viscous fluid in packing are analyzed. Furthermore, a correlation is developed to predict the specific area of liquid in terms of dimensionless numbers. This work provides a fundamental reference for realizing the interfacial characteristics in packed columns involving highly viscous fluids.