Modeling of laminar-turbulent stratified liquid–liquid flow with entrainment

Abstract

An one-dimensional model is developed for liquid–liquid flows considering a stratified flow where droplet entrainment is present. Two models from literature were used as a starting point: one that is well suited for stratified wavy flows and another that adds entrainment effects. In the development, an important intermediate step is introduced to correct wetted perimeters and interface position, which is particularly important when one of the phases has a high viscosity. The entrainment factors and rates are evaluated to assess their relevance for the typical flow case studied. Experimental data are gathered for comparison and validation purposes, and to act as closure information to the model. The predictions of the model are also compared against CFD simulations using a VOF based approach. The results are promising and suggest that the 1D model can be better suited for some applications, leading to great accuracy at a much lower processing cost than the CFD method applied.