CFD simulation with experimental validation of oil-water core-annular flows through Venturi and Nozzle flow meters

In the present study, Volume of Fluid (VOF) multiphase flow model by ANSYS Fluent 16.2 is used to characterize core-annular flow patterns of highly-viscous oil-water flows through a Venturi Flow Meter (VFM) and a Nozzle Flow Meter (NFM) in a 40 mm i.d. horizontal pipe. Numerical simulations are compared with experiments, for oil superficial velocities in the range 0.25-0.75 m s−1 and water superficial velocities in the range 0.44-1.32 m s−1. Eight cases were considered for numerical runs. Two turbulence models were considered, namely realizable k−ε and Shear Stress Transport ((SST)k−ω. Two phase pressure drop, instantaneous radial velocity and holdup profile, cross-sectional time-averaged holdup and slip ratio were extracted from CFD simulations. Flow patterns were also compared to actual images taken by a Olympus E-M10 mirrorless camera. In terms of concentrated pressure drop and mean water holdup, the results of CFD simulations are consistent with the experimental data. Prediction of the total mass flow rate, computed by homogeneous model, for both the VFM and NFM also gave very satisfactory results.