Study of kerosene–water two‐phase flow characteristics in vertical and inclined pipes

Abstract

The kerosene–water flow in vertical and inclined pipes of 77.8 mm inner diameter and 4500 mm length has been investigated numerically. Simulations were carried out at three inclination angles of 0°, 5° and 30° from vertical for superficial water velocities in the range of 0.29–1.6 m/s and volumetric qualities in the range of 9.2–65.5%. Results from the simulations have been compared with the corresponding experimental data from our previous study to check the suitability of meshing, physical models and boundary conditions used. The results from CFD predictions show a reasonable agreement with the experimental data for the vertical pipe. Some discrepancies have been observed near the walls for inclined pipes as the flow becomes more complex with the appearance of drops swarms. The same computational domain was then used to investigate the effect of a higher volumetric quality and superficial water velocity on the flow characteristics. The axisymmetrical distribution of the volume fraction, water velocity and drops velocity which were observed in the vertical pipe has changed into asymmetrical distribution in the inclined pipe. It has also been observed that increasing the superficial water velocity and volumetric quality modifies the distributions of flow parameters due to the movement of kerosene drops toward the lower part of the pipe. The results from CFD predictions on the volume fraction distribution at 30° inclination indicate the appearance of phase inversion phenomenon when the volumetric quality becomes greater than 65%.

The Effect of Downstream Flow Resistance for Kerosene and Water Separation on Efficiency T-Junction

“…This condition occurs when the flow resistance is set downstream through a valve. In addition, the regulation of superficial kerosene velocity and superficial water velocity results in the formation of different flow patterns at the T-junction inlet which affects the efficiency of phase separation (Yang;et al, 2019) (Hamad;et al, 2015). In this study, at a superficial water velocity of 0.1 m/s and a kerosene flow velocity of 0.1 m/s, the flow is stratified.…”

CFD simulation of interfacial instability from the nozzle in the formation of viscous core‐annular flow

“…There are three numerical models which are used to solve two‐phase flow problems: the volume of fluid model (VOF), the Mixture model, and the Eulerian model. The VOF model is selected for this case of the hydrodynamics of core annular flow and it has been widely used for two‐phase modelling .…”

“…The standard k‐ϵ model has been used for gas‐liquid with a low Reynolds number . Among the turbulent models available in Fluent, the standard k‐ϵ model has been selected to simulate the liquid‐liquid flow . This model estimates the turbulent kinetic energy (k) and the viscous dissipation rates (ϵ) which are used to obtain the turbulent viscosity in the flow field.…”

“…y + is defined as the dimensional wall distance obtained by the ratio of stress velocity and cinematic viscosity (y + = yU τ /v), values between 30 and 300 are appropriate. y + being close to the lower bound (y ≈ 30) is desirable for wall function …”

Coalescence and rising behavior of co‐axial and lateral bubbles in viscous fluid: a CFD study

“…A number of experimental studies have been reported on co‐axial bubbles (or a pair of bubbles rising in a vertical line) and their coalescence . For example, Katz and Meneveau experimentally investigated the rising motion of air bubbles in stagnant water at Reynolds number, Re = V ρ d o / μ , ranging from 0.2 to 35 and found that the collision between bubbles resulted mainly from wake‐induced relative motion.…”