A Three-Dimensional Model of Turbulent Core Annular Flow Regime

Abstract

In this study, three-dimensional (3D) turbulent core annular flow (CAF) regime is investigated numerically. The proposed model is based on the 3D Reynolds average Navier–Stokes (RANS) equations combined with a pure convective transport equation of the volume of fluid (VOF) to predict the interface between the oil and water phases. The k-ω turbulence model is adopted to better reproduce the oil and water flow characteristics. The two-phase (CAF) regime can be predicted by two inlet configurations: the T-junction (3D-T) and the straight pipe (3D-S). These two configurations are simulated and compared for pipe diameter $D=0.026\text{\hspace{0.17em}m}$ and pipe length $L=4\text{\hspace{0.17em}m}$ . For these two inlet configurations, the computed mixture velocity profile and the water volume fraction at a test section $\left(z=100\text{\hspace{0.17em}D}\right)$ were compared to experimental measurements. The 3D-T configuration gives more appropriate results. The 3D-S slightly overestimates the maximum velocity at the test section and the lower and upper water layer of the (CAF) flow is shifted in the upward direction. For the 3D-T, the relative error in the pressure drop is 3.3%. However, for the 3D-S, this error is 13.0%.