Numerical analysis of two-phase flow from a stratified region through a small circular side branch

• Published in: International journal of multiphase flow 2016-12, Vol.87, p.175-183
• Main Authors: Guyot, M.K., Ormiston, S.J., Soliman, H.M.
• Format: Article
• Language: English
• Subjects: CFD model assessment; Discharge through a side branch; Gas–liquid; Two-phase flow
• ISSN: 0301-9322; 1879-3533
• DOI: 10.1016/j.ijmultiphaseflow.2016.09.009

•3D CFD analysis of steady two-phase gas-liquid flow from a stratified region in a tank to a circular side branch•good agreement with previous correlations for gas and liquid entrainment onset heights•detailed results are used to give insights into the flow behaviour just before the onsets of gas and liquid entrainment•computations required significant resources A numerical analysis using a commercial CFD code, ANSYS CFX, was used to model two-phase flow discharging from a stratified region through a small branch of circular cross-section. The purpose of this study is to assess the capability of the code in predicting the pertinent flow parameters and to generate detailed results that can provide insights into some of the flow phenomena. The inhomogeneous, free surface model was used and the code predictions were evaluated by comparing results with previous correlation equations and experimental data. Results were obtained for the critical heights of the interface at the onsets of gas and liquid entrainment, as well as the mass flow rate and quality during two-phase discharge. Additional results including force balances and pressure contours were also analysed to provide insight into the flow characteristics just before the onsets of liquid and gas entrainment. All results are in good agreement with existing correlation equations and experimental data. CFD modelling is therefore a possible tool for predicting the correct results for discharging two-phase flow for the geometry under consideration; the computation time required to obtain converged results, however, was found to be excessive.