Semi-Emperical Model to Determine Liquid Velocity and Pressure Loss of Two-Phase Flow in A Horizontal Bend–Part I (Stratified Flow)

Abstract

The objectives of this study are to conduct a thorough literature review on the subject of multiphase flow through bends and to develop and evaluate a semi-empirical model to determine liquid velocity and pressure loss during stratified gas-liquid flow in a horizontal bend. The model is based on incorporating the momentum balance equations of both phases (air and water). Extensive experiments were carried out to acquire data using air and water in a 0.05 m diameter horizontal pipe simulator with an intermediate bend of 0.5 m radius of curvature.The results show that due to the disturbance nature of the two-phase flow in general, it is quite convenient to describe the pressure drop in terms of the energy loss. It was also found that stratified flow does not cause a significant change in the energy during the flow along the bend traverse due to its stable nature. The semi-empirical model developed for predicting the superficial water velocity during stratified flow shows an acceptable agreement with the experimental data.The work presented in this paper may help flow assurance, production, pipeline and process engineers to have reliable design and operations through counting for the losses caused by such components.

Developing a 3D CFD Code to Simulate Incompressible Simultaneous Two-Phase Flow through a Horizontal Bend Using VOF Principle

“…The liquid film variations shown in these results reveals the fact that it's build up upstream of the bend part is the main reason for slug formation. The results of these simulations are consistent with the findings presented in [1], [3], [4].…”

“…In order to qualify the outcomes of the code, simulation results have been compared with the results acquired from three different techniques developed for the same project. These techniques were: 1) High-accuracy pressure sensors used to probe pressure variation along the bend [1]; 2) Fiber optic sensing system (with Laser) used to determine the liquid film thickness and interfacial wave velocity [3]; and 3) High-speed video imaging system developed to determine the interfacial wave velocity [4]. The comparison showed a reasonable agreement.…”