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

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

Study of Particulate Flow in the Impeller of a Slurry Pump Using PIV

Volume 1 ◽  
2004 ◽  
Author(s):  
M. Mehta ◽  
J. R. Kadambi ◽  
S. Sastry ◽  
J. Sankovic ◽  
M. Wernet ◽  
...  
Keyword(s):  
Suction Side ◽  
Solid Particles ◽  
Working Fluid ◽  
Clear Fluid ◽  
Pump Speed ◽  
Velocity Magnitude ◽  
Index Matching ◽  
Refractive Index Matching ◽  
Blade Tip ◽  
Particle Velocities

Particle Image Velocimetry (PIV) technique in conjunction with refractive index matching was successfully utilized to investigate the velocities of the slurry particles in the impeller of a centrifugal slurry pump. Tests were performed in an optically clear centrifugal slurry pump at speeds of 725 rpm and 1000 rpm using a slurry made up of sodium iodide solution as the working fluid and glass beads (500μm mean diameter) as solid particles at volumetric concentrations of 1%,2%, and 3%. In the intra blade region of the impeller, the highest particle velocities were obtained on the suction side of the blade and in the blade trailing edge region as the blade sweeps through and velocity magnitude increases with the pump speed. But this magnitude was less than that of circumferential velocity of the blade tip. Relative velocity plots show that flow separation takes place on the suction side of the blade in the region below the blade tip for clear fluid flow conditions. This was expected as the pump is made to operate with a slurry and not a single-phase liquid. At higher pump speeds and particle volumetric concentrations, a marked improvement in the slurry flow in the impeller is observed i.e., the recirculation zone decreases. This results from the centrifugal forces on the particles and its inertia at that speed. Also the slurry particles are pushed on the pressure side of the blade and slide along it which can result in frictional wear. These results are discussed in this paper.

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.

A Combined Numerical and Experimental Study of Air Bubble Dynamics in Converging Section of Effervescent Atomizer

2015 ◽  
Author(s):  
Deify Law ◽  
Thomas Shepard ◽  
Ibrahim Wardi
Keyword(s):  
High Speed ◽  
Bubble Dynamics ◽  
Imaging System ◽  
Cross Flow ◽  
High Speed Imaging ◽  
Two Phase ◽  
Significant Drop ◽  
Convergent Channel ◽  
Air Bubble ◽  
Effervescent Atomizer

Inside of an effervescent atomizer gas is injected into a liquid cross-flow in order to produce a bubbly two-phase mixture. The presence of gas bubbles leads to enhanced liquid break-up as compared to simple pressure atomization of the liquid phase alone [1]. In the present work, the dynamic shapes and sizes of single air bubbles injected in liquid water cross flow of an effervescent atomizer’s mixing chamber are investigated numerically and experimentally. Particular focus is aimed on the convergent channel section just prior to the atomizer exit orifice where the bubble experiences a significant drop in pressure. Volume of fluid (VOF) modeling and simulations are performed using the commercial computational fluid dynamics (CFD) code ANSYS FLUENT and further provide information on the liquid velocities near the air bubble. A high-speed imaging system and digital image processing are used for capturing experimental data on this highly dynamic process. The numerical results are compared with experimental visualizations to better understand the physical interactions between the two phases approaching the atomizer exit.

Interfacial circulation due to surface-active agents in steady two-phase flows

1966 ◽  
Vol 24 (2) ◽  
pp. 293-306 ◽  
Author(s):  
D. B. R. Kenning ◽  
M. G. Cooper
Keyword(s):  
Open Channel ◽  
Tap Water ◽  
Surface Film ◽  
Active Material ◽  
Two Phase ◽  
Measured Velocity ◽  
Air Bubble ◽  
Surface Active Agents ◽  
Surface Active ◽  
Surface Active Material

Steady circulatory motions at the surface of tap-water flowing in an open channel and past a hemispherical air bubble on a channel wall are described and explained by the presence of a film of surface-active material. Boundary conditions for the liquid phase are derived by assuming that the surface film is insoluble and incompressible. Good agreement is obtained between the theoretical and measured velocity fields in the open-channel flow.

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.

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