Abstract
In this article, the commercial software COMSOL multiphysics 5.0 was used to model and simulate 2D core annular flow (CAF) between oil and water flow in a horizontal pipe. The objective was to obtain the flow volume, velocity, shear rate, and pressure profiles of nine different kinds of oils (ranging from heavy to light) found in published articles, and explain them using density-viscosity magnitudes. Interestingly, those magnitudes and their application in describing multiphase volume pressure, velocity were the main novelties of this paper. Thus, the magnitudes were calculated through multiplying the densities of oils by their respective viscosities. However, for convenience, dimensionless forms of these magnitudes were also calculated through further division of oil density-viscosity magnitudes by that of water. Using those magnitudes, it was possible to explain the numerical results of flow volume, velocity, shear rate, and pressure profiles obtained in this article. Notably, analyses of the results showed that larger magnitudes (above 500, using the dimensionless magnitude) produce core annular flows (CAF), while lower magnitudes (below 10 using the dimensionless magnitude) produce other flow profiles (such as dispersed, slug, and plug). The numerical study was carried out using two-phase laminar Level-set method, which was successfully validated by reproducing volume, velocity, pressure, and shear stress (product of shear rate and viscosity) profiles that were found in two published articles.
