scholarly journals CFD STUDY OF TWO-PHASE SLUG FLOW DEVELOPMENT IN HORIZONTAL PIPE

2020 ◽  
Author(s):  
Carla Nayara Michels dos Santos ◽  
Sarah Laysa Becker ◽  
Vinícius Basso de Godoy ◽  
Celso Murilo dos Santos ◽  
Henry França Meier ◽  
...  
Keyword(s):  
Slug Flow ◽  
Two Phase ◽  
Horizontal Pipe ◽  
Flow Development

Experimental Characterization of Slug Flow Velocity Distribution in Two Phase Pipe Flow

2009 ◽  
Author(s):  
Afshin Goharzadeh ◽  
Peter Rodgers
Keyword(s):  
Velocity Distribution ◽  
Slug Flow ◽  
Two Phase ◽  
Significant Drop ◽  
Horizontal Pipe ◽  
Measured Velocity ◽  
Air Bubble ◽  
Velocity Magnitude ◽  
Index Matching ◽  
Refractive Index Matching

This paper presents an experimental study of gas-liquid slug flow inside a horizontal pipe. The influence of air bubble passage on liquid flow is characterized using Particle Image Velocimetry (PIV) combined with Refractive Index Matching (RIM) and fluorescent tracers. A physical insight into the velocity distribution within slug flow is presented. It was observed that the slug flow significantly influences the velocity profile in the liquid film. Measured velocity distributions also revealed a significant drop in the velocity magnitude immediately upstream of the slug nose. These findings aim to aid an understanding of the mechanism of solid transportation in slug flows.

scholarly journals Statistical characterization of two-phase slug flow in a horizontal pipe

2011 ◽  
Vol 33 (spe1) ◽  
pp. 251-258 ◽  
Author(s):  
J. N. E. Carneiro ◽  
R. Fonseca Jr. ◽  
A. J. Ortega ◽  
R. C. Chucuya ◽  
A. O. Nieckele ◽  
...  
Keyword(s):  
Slug Flow ◽  
Two Phase ◽  
Horizontal Pipe ◽  
Statistical Characterization

Numerical Investigation of Slug Flow in a Horizontal Pipe Using a Multi-Scale Two-Phase Approach to Incorporate Gas Entrainment Effects

2016 ◽  
Author(s):  
Stefan Wenzel ◽  
Marek Czapp ◽  
Thomas Sattelmayer
Keyword(s):  
Flow Regime ◽  
Slug Flow ◽  
Fluid Model ◽  
Interfacial Area ◽  
Experimental Investigations ◽  
Multiscale Approach ◽  
Two Phase ◽  
Horizontal Pipe ◽  
Horizontal Pipes ◽  
Interface Capturing

Numerical as well as experimental investigations of the highly intermittent slug flow regime of a gas-liquid mixture in horizontal pipes are of particular interest for nuclear reactor safety in post loss-of-coolant accident (LOCA) situations. The strong variation of governing interfacial length scales, as they are characterizing the slug flow regime, pushes common numerical multi-phase approaches to their limits, since they are designed either for interface capturing or for modeling the sub-grid behavior of the dispersed mixture. In this work an enhanced hybrid two-phase flow solver is employed to investigate the global and local characteristics of adiabatic, horizontal slug flows in a water-air system. A dynamic switching algorithm for an interface capturing procedure is introduced to examine segregated and dispersed parts in the same flow domain. The inter-facial area transport equation (IATE) is used to detect dispersed flow regions as well as to determine variable bubble sizes and their distribution within the slug body. Experimental results of videometry measurements on a horizontal, 10 m long pipe with an inner diameter of 54 mm at atmospheric pressure and room temperature are compared with numerical results of the same geometry in terms of global characteristics such as slug frequency and onset position. Local properties, such as the interfacial area density in the slug body, are also examined. This study demonstrates the capability of a coupled multiscale approach based on the Euler-Euler two-fluid model (TFM) for the simulation of slug flow in horizontal pipes with a high amount of entrainment.

Numerical Simulation of the Transient Development of Slug Flow in Horizontal Pipes

2016 ◽  
Vol 819 ◽  
pp. 300-304 ◽  
Author(s):  
Zahid Ibrahim Al-Hashimy ◽  
Hussain H. Al-Kayiem ◽  
Mohammad Shakir Nasif ◽  
Abdalellah. O. Mohmmed
Keyword(s):  
Flow Regime ◽  
Slug Flow ◽  
Two Phase Flow ◽  
Piping System ◽  
Phase Flow ◽  
Two Phase ◽  
Horizontal Pipe ◽  
Horizontal Pipes ◽  
Flow Phenomena ◽  
Multi Phase Flow

Slug flow regime in two and multi-phase flow in pipes is a complicated flow phenomena representing challenge in the design of the piping system. In the present work, water/air two phase flow was modeled and simulated as 3 dimensional, transient, and incompressible flow using Volume of Fluid technique in STAR-CCM+ software. The simulation was conducted to predict and evaluate the air-water slug flow in a horizontal pipe with 0.16 m diameter and 7 m long. The superficial velocities for both phases were extracted from Baker chart slug zone. The results were validated against experimental bench marking referenced in Baker chart and the proposed VOF technique shows a good capability in simulating the development of the slug flow regime. This model could be utilized for simulation of various two phase flow regimes.

scholarly journals Two-Phase Flow Development of R134a in a Horizontal Pipe: Computational Investigation

2021 ◽  
Vol 39 (5) ◽  
pp. 1532-1540
Author(s):  
Raid A. Mahmood ◽  
Khalid Saleh ◽  
Veyan A. Musa ◽  
Enass Massoud ◽  
Ahmad Sharifian-Barforoush ◽  
...  
Keyword(s):  
Two Phase Flow ◽  
Three Dimensional ◽  
Phase Flow ◽  
Vapor Quality ◽  
Computational Investigation ◽  
Two Phase ◽  
Horizontal Pipe ◽  
Flow Development ◽  
Flash Tank ◽  
Region Length

To improve the performance of vapor compression refrigeration systems that use vertical gravitational flash tank separators, the liquid separation efficiency of the vertical gravitational flash tank separator requires to be approved. To approach this improvement, the two-phase flow development and its behavior after the expansion device need to be investigated and predicted. For thus, this paper presents a three-dimensional computational investigation of the two-phase flow development of R134a after the expansion device in a horizontal pipe. Computational Fluid Dynamic (CFD) was used to predict the two-phase development and its behavior in the horizontal pipe. ANSYS 16.2 program was used to generates the geometry of the three-dimensional horizontal pipe of 2 meters long and 25 mm inner diameter. The hexahedral mesh was generated and it is assessed to obtain the optimum mesh size and number. Eulerian-Eulerian two-phase model was used with k-ɛ turbulence model. R134a was used as a working fluid in the horizontal pipe utilizing four different inlet diameters: 12, 12.5, 25, and 50.0 mm. Mass flux and vapor quality have been changed from 288 to 447 kg/m2.s and from 10 to 20% respectively. Results were validated against experimental results from the literature and revealed that the separation region length is affected by the initial phase velocities, inlet vapor quality, and inlet tube diameter. An empirical correlation to predict the expansion region length is proposed as a function of Froude, Webber, and Lockhart-Martinelli numbers.

scholarly journals Simulation Study on the Development Process and Phase Interface Structure of Gas-Liquid Slug Flow in a Horizontal Pipe

2021 ◽  
Vol 9 ◽  
Author(s):  
Xiao Wu ◽  
Zhaoting Wang ◽  
Mei Dong ◽  
Quan Ge ◽  
Longfei Dong
Keyword(s):  
Velocity Field ◽  
Slug Flow ◽  
Development Process ◽  
Pressure Fluctuations ◽  
Phase Interface ◽  
Interface Structure ◽  
Liquid Slug ◽  
Two Phase ◽  
Horizontal Pipe ◽  
Open Source Software Package

Here, a unified 3D numerical model of gas-liquid two-phase flow in a horizontal pipe was established using the interface capture method based on the open source software package OpenFOAM. Through numerical simulation of the natural slugging and development process of slug flow under different working conditions, the motion, phase interface structure, pressure and velocity field distributions of the liquid slug were fully developed and analyzed. The simulation results are consistent with the experiment. The results showed that during the movement of the slug head, there is a throwing phenomenon and a wave-like motion of the liquid slug. In addition, the slug tail and body area have very similar velocity profiles, and the overall velocity field distribution becomes more uniform with the development of liquid slug. Moreover, there are sudden pressure fluctuations at the head and tail of the liquid slug.

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