Hydrodynamics of the rivulet flow over corrugated sheet used in structured packings

Abstract

A key factor influencing the overall efficiency in a structured packed column, such as used for solvent absorption, is wetting of the corrugated sheets. Computational fluid dynamics modeling of solvent absorption is a multi-scale problem with flow over a corrugated sheet providing a relatively simple setup to investigate the microscale flow phenomena present in these complex systems. Accordingly, multiphase flow simulations of rivulet flow over a corrugated sheet were systematically carried out over a wide range of solvent physical properties and contact angles using the volume of fluid method. A scaling analysis for wetted and interfacial areas was performed on the simulation results, and a theory for interfacial area in terms of Kapitza number is proposed. The advantage of the Kapitza number is that it only depends on fluid properties and is independent of flow parameters. The results show that the interfacial area of the rivulet decreases as the Kapitza number increases for a given contact angle and flow rate. The effects of the corrugation angle on the interfacial area were also extensively investigated. The interfacial area shows non-monotonic variation with increasing corrugation angle, i.e, it first increases until 45° and then it decreases. Hence, 45° can be considered the optimum corrugation angle for enhanced interfacial area in this setup.