Comparison of Computational Fluid Dynamics Simulations and Experiments for Stratified Air-Water Flows in Pipes

Abstract

Stratified gas–liquid flow is a flow regime typically encountered in multiphase pipelines. The understanding and modeling of this regime is of engineering importance especially for the oil and gas industry. In this work, simulations have been conducted for stratified air–water flow in pipes. We solved the Reynolds-averaged Navier–Stokes (RANS) equations with the volume of fluid (VOF) method. The aim of this work was to evaluate the performance of the k–ω shear stress transport (SST) turbulence model with and without damping of the turbulence at the gas–liquid interface. Simulation results were compared with some of the latest experimental results found in the literature. A comparison between the simulated velocity and kinetic energy profiles and the experimental results obtained with the particle image velocimetry (PIV) technique was conducted. The characteristics of the interfacial waves were also extracted and compared with the experiments. It is shown that a proper damping of the turbulence close to the interface is needed to obtain agreement with the experimental pressure drop and liquid hold-up. In its current form, however, RANS with the k–ω turbulence model is still not able to give an accurate prediction of the velocity profiles and of the interface waves.

Numerical study of pipeline leak detection for gas-liquid stratified flow

“…The simulation results are validated against the numerical simulation by Chinello et al (2019) and experimental data reported in Espedal (1998). In particular, monophase and stratified flow behaviours induced by leaks are compared and validated with the experimental data reported by Monina-Espinosa et al (2013).…”

“…The VOF method, which is a one-fluid approach, comprises the continuity and momentum equations which are given in Equations ( 1) and (2), respectively (Chinello et al, 2019):…”

CFD study and experimental validation of low liquid-loading flow assurance in oil and gas transport: studying the effect of fluid properties and operating conditions on flow variables

“…They have only focused on stratified flows of water-air mixtures at atmospheric conditions, and the Computational Fluid Dynamic (CFD) models have not predicted flow conditions accurately with small liquid holdups (Ghorai and Nigam, 2006;Kumar and Ming Bing, 2011;Karami et al, 2014). Even some of the most recent studies, such as Chinello et al(2019) andL opez et al (2016), simulated only liquid holdups over 10% and even then reported errors of up to 30% for flows whose holdups were near this threshold value.…”

The effect of air velocity on slugs in a confined channel

“…They revealed that the rapid increase in pressure is related to the length of the slugs. In addition to the experimental studies, several numerical studies were carried out on two-phase flows [32]- [41].…”

“…The results obtained using the VOF model agree well with the experimental data, especially for low gas velocities. Other research [34]- [36], [41] examined the ability of numerical models to predict the development and characteristics of intermittent flows (slug flow and plug flow). Nasrfard et al [34] simulated two-phase flow in a 14.4 m long pipe with an inside diameter of 54 mm.…”