Numerical Study of Single Taylor Bubble Movement Through a Microchannel Using Different CFD Packages

Abstract

A Computation Fluid Dynamics (CFD) study for micro-scale gas–liquid flow was performed by using two different software packages: OpenFOAM® and ANSYS Fluent®. The numerical results were compared to assess the capability of both options to accurately predict the hydrodynamics of this kind of system. The focus was to test different methods to solve the gas–liquid interface, namely the Volume of Fluid (VOF) + Piecewise Linear Interface Calculation (PLIC) (ANSYS Fluent®) and MULES/isoAdvector (OpenFOAM®). For that, a single Taylor bubble flowing in a circular tube was studied for different co-current flow conditions (0.01 < CaB < 2.0 and 0.01 < ReB < 700), creating representative cases that exemplify the different sub-patterns already identified in micro-scale slug flow. The results show that for systems with high Capillary numbers (CaB > 0.8) each software correctly predicts the main characteristics of the flow. However, for small Capillary numbers (CaB < 0.03), spurious currents appear along the interface for the cases solved using OpenFOAM®. The results of this work suggest that ANSYS Fluent® VOF+PLIC is indeed a good option to solve biphasic flows at a micro-scale for a wide range of scenarios becoming more relevant for cases with low Capillary numbers where the use of the solvers from OpenFoam® are not the best option. Alternatively, improvements and/or extra functionalities should be implemented in the OpenFOAM® solvers available in the installation package.