Two-Phase Flow-Induced Forces on Bends in Small Scale Tubes

2009 ◽  
Author(s):  
Marcos F. Cargnelutti ◽  
Stefan P. C. Belfroid ◽  
Wouter Schiferli
Keyword(s):  
Experimental Data ◽  
Slug Flow ◽  
Structural Integrity ◽  
Two Phase Flow ◽  
Small Scale ◽  
Phase Flow ◽  
Mechanical Forces ◽  
Two Phase ◽  
Or Efficiency ◽  
Flow Induced Vibrations

Two-phase flow occurs in many situations in industry. Under certain circumstances, this can be the source of flow-induced vibrations. The forces generated can be sufficiently large to affect the performance or efficiency of an industrial device. At worst, the mechanical forces that arise may endanger structural integrity. Thus, it is important to take these forces into account in designing industrial machinery to avoid problems during operation. Although the occurrence of such forces is well-known, not much is known about their magnitudes. Unfortunately, the amount of experimental data available in literature is rather limited. This paper describes an investigation into the forces in a two-phase flow in a 6mm pipe containing a bend. The results are analyzed based on flow regime and bend configuration. Finally, a simple model is proposed to predict the forces generated by slug flow.

Two-Phase Flow-Induced Forces on Bends in Small Scale Tubes

2010 ◽  
Vol 132 (4) ◽  
Author(s):  
M. F. Cargnelutti ◽  
S. P. C. Belfroid ◽  
W. Schiferli
Keyword(s):  
Experimental Data ◽  
Structural Integrity ◽  
Two Phase Flow ◽  
Experimental Results ◽  
Small Scale ◽  
Phase Flow ◽  
Momentum Exchange ◽  
Two Phase ◽  
Worst Case ◽  
Good Agreement

Two-phase flow occurs in many situations in industry. Under certain circumstances, it can be a source of flow-induced vibrations. The forces generated can be sufficiently large to affect the performance or efficiency of an industrial device. In the worst-case scenario, the mechanical forces that arise may endanger structural integrity. Thus, it is important to take these forces into account in designing industrial machinery to avoid problems during operation. Although the occurrence of such forces is well known, not much is known about their magnitudes because, unfortunately, the amount of experimental data available in literature are rather limited. This paper describes the experiments performed to measure forces in 6 mm diameter tubing containing a bend. Experiments are performed on bends of different radii, with the bend positioned horizontally or vertically. The experimental results are analyzed based on flow regime and bend configuration. A comparison with available experimental results for bigger internal pipe diameter shows a general good agreement. To improve future predictions, a simple model based on momentum exchange is proposed to estimate the forces generated by multiphase flow. The proposed model shows a good agreement with the experimental data.

scholarly journals Slug Flow Hydrodynamics Modeling for Gas–Liquid Two-Phase Flow in a Pipe

Energies ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 533
Author(s):  
Huishu Liu ◽  
Jimiao Duan ◽  
Kecheng Gu ◽  
Jiang Li ◽  
Hao Yan ◽  
...  
Keyword(s):  
Experimental Data ◽  
Slug Flow ◽  
Two Phase Flow ◽  
Close Contact ◽  
Liquid Droplet ◽  
Flow Patterns ◽  
Phase Flow ◽  
Interface Model ◽  
Two Phase ◽  
Model Calculations

Gas–liquid flow in a pipeline is a very common. Slug two-phase flow is dominated in the case of slightly upward flow (+0.25°) and considered to be the comprehensive flow configuration, and can be in close contact with all the other flow patterns. The models of different flow patterns can be unified. Precise prediction of the slug flow is crucial for proper design and operation. In this paper, we develop hydrodynamics unified modeling for gas–liquid two-phase slug flow, and the bubble and droplet entrainment is optimized. For the important parameters (wall and interfacial friction factors, slug translational velocity and average slug length), the correlations of these parameters are optimized. Furthermore, the related parameters for liquid droplet and gas bubble entrainment are given. Accounting for the gas–liquid interface shape, hydrodynamics models, i.e., the flat interface model (FIM) and the double interface model (DIM), of liquid film in the slug body are applied and compared with the experimental data. The calculated results show that the predictions for the liquid holdup and pressure gradient of the DIM agree with experimental data better than those of the FIM. A comparison between the available experimental results and Zhang’s model calculations shows that the DIM model correctly describes the slug dynamics in gas–liquid pipe flow.

On Instabilities in Horizontal Two-Phase Flow

1994 ◽  
Vol 59 (12) ◽  
pp. 2595-2603
Author(s):  
Lothar Ebner ◽  
Marie Fialová
Keyword(s):  
Differential Equation ◽  
Flow Regime ◽  
Slug Flow ◽  
Annular Flow ◽  
Two Phase Flow ◽  
Phase Flow ◽  
Two Phase ◽  
Annular Flows ◽  
Flow Regime Maps

Two regions of instabilities in horizontal two-phase flow were detected. The first was found in the transition from slug to annular flow, the second between stratified and slug flow. The existence of oscillations between the slug and annular flows can explain the differences in the limitation of the slug flow in flow regime maps proposed by different authors. Coexistence of these two regimes is similar to bistable behaviour of some differential equation solutions.

scholarly journals Experimental data for the slug two-phase flow characteristics in horizontal pipeline

Data in Brief ◽  
2018 ◽  
Vol 16 ◽  
pp. 527-530 ◽  
Author(s):  
Abdalellah O. Mohmmed ◽  
Mohammad S. Nasif ◽  
Hussain H. Al-Kayiem
Keyword(s):  
Experimental Data ◽  
Two Phase Flow ◽  
Flow Characteristics ◽  
Phase Flow ◽  
Two Phase

scholarly journals Investigation of representing hysteresis in macroscopic models of two-phase flow in porous media using intermediate scale experimental data

2017 ◽  
Vol 53 (1) ◽  
pp. 199-221 ◽  
Author(s):  
Abdullah Cihan ◽  
Jens Birkholzer ◽  
Luca Trevisan ◽  
Ana Gonzalez-Nicolas ◽  
Tissa Illangasekare
Keyword(s):  
Experimental Data ◽  
Porous Media ◽  
Two Phase Flow ◽  
Flow In Porous Media ◽  
Phase Flow ◽  
Two Phase ◽  
Intermediate Scale ◽  
Macroscopic Models

Effect of Common Impurities on the Phase Behavior of Carbon-Dioxide-Rich Systems: Minimizing the Risk of Hydrate Formation and Two-Phase Flow

SPE Journal ◽  
2011 ◽  
Vol 16 (04) ◽  
pp. 921-930 ◽  
Author(s):  
Antonin Chapoy ◽  
Rod Burgass ◽  
Bahman Tohidi ◽  
J. Michael Austell ◽  
Charles Eickhoff
Keyword(s):  
Experimental Data ◽  
Carbon Dioxide ◽  
Phase Behavior ◽  
Water Content ◽  
Thermodynamic Model ◽  
Two Phase Flow ◽  
Hydrate Formation ◽  
Experimental Methodology ◽  
Phase Flow ◽  
Two Phase

Summary Carbon dioxide (CO2) produced by carbon-capture processes is generally not pure and can contain impurities such as N2, H2, CO, H2 S, and water. The presence of these impurities could lead to challenging flow-assurance issues. The presence of water may result in ice or gas-hydrate formation and cause blockage. Reducing the water content is commonly required to reduce the potential for corrosion, but, for an offshore pipeline system, it is also used as a means of preventing gas-hydrate problems; however, there is little information on the dehydration requirements. Furthermore, the gaseous CO2-rich stream is generally compressed to be transported as liquid or dense-phase in order to avoid two-phase flow and increase in the density of the system. The presence of impurities will also change the system's bubblepoint pressure, hence affecting the compression requirement. The aim of this study is to evaluate the risk of hydrate formation in a CO2-rich stream and to study the phase behavior of CO2 in the presence of common impurities. An experimental methodology was developed for measuring water content in a CO2-rich phase in equilibrium with hydrates. The water content in equilibrium with hydrates at simulated pipeline conditions (e.g., 4°C and up to 190 bar) as well as after simulated choke conditions (e.g., at -2°C and approximately 50 bar) was measured for pure CO2 and a mixture of 2 mol% H2 and 98 mol% CO2. Bubblepoint measurements were also taken for this binary mixture for temperatures ranging from -20 to 25°C. A thermodynamic approach was employed to model the phase equilibria. The experimental data available in the literature on gas solubility in water in binary systems were used in tuning the binary interaction parameters (BIPs). The thermodynamic model was used to predict the phase behavior and the hydrate-dissociation conditions of various CO2-rich streams in the presence of free water and various levels of dehydration (250 and 500 ppm). The results are in good agreement with the available experimental data. The developed experimental methodology and thermodynamic model could provide the necessary data in determining the required dehydration level for CO2-rich systems, as well as minimum pipeline pressure required to avoid two-phase flow, hydrates, and water condensation.

Study of the 90° Elbows Performance as Phase Separators in an Air-Water Two-Phase Flow

2003 ◽  
Author(s):  
Valente Herna´ndez P. ◽  
Florencio Sa´nchez S. ◽  
Miguel Toledo V. ◽  
Georgiy Polupan
Keyword(s):  
Phase Separation ◽  
Slug Flow ◽  
Two Phase Flow ◽  
Phase Flow ◽  
Pressure Gradients ◽  
Two Phase ◽  
Branch Diameter ◽  
Independent Variables ◽  
Inclination Angles ◽  
Phase Separator

In order to observe the 90° elbows performance as phase separators in an air-water two-phase flow, experimental results for the phase split which occurs at a 90° branched elbow are presented. The branched elbow geometry was varied in order to have three (branch diameter / elbow diameter) ratios and three branch inclination angles. Also the pressure was monitored at different points of the elbow with ramification in order to examine the pressure drop effect. The flow pattern upstream was mainly slug flow. First, the analysis of the main independent variables effect, (superficial velocities, branch inclination angle, ratio of diameters and pressure gradients) was carried out, then a correlation for the phase split was developed and, finally a comparison was made with data of phase separation in T junctions obtained by Azzopardi [1] and Soliman [2], as a result, a better behavior as phase separator was found for the elbow.

Evaluation of Length Scales and Meshing Requirements for Resolving Two-Phase Flow Regime Transitions Using the Level Set Method

2021 ◽  
Author(s):  
Matt Zimmer ◽  
Igor A Bolotnov
Keyword(s):  
Thin Films ◽  
Flow Regime ◽  
Level Set Method ◽  
Level Set ◽  
Two Phase Flow ◽  
Small Scale ◽  
Phase Flow ◽  
Two Phase ◽  
Interface Capturing ◽  
Regime Transitions

Abstract New criteria for fully resolving two-phase flow regime transitions using direct numerical simulation with the level set method for interface capturing are proposed. A series of flows chosen to capture small scale interface phenomena are simulated at different grid refinements. These cases include droplet deformation and breakup in a simple shear field, the thin film around a Taylor bubble, and the rise of a bubble towards a free surface. These cases cover the major small scale phenomena observed in two-phase flows: internal recirculation, interface curvature, interface snapping, flow of liquid in thin films, and drainage/snapping of thin films. The results from these simulations and their associated grid studies were used to develop new meshing requirements for simulation of two-phase flow using interface capturing methods, in particular the level set method. When applicable, the code used in this work, PHASTA, was compared to experiments in order to contribute to the ongoing validation process of the code. Results show that when the solver meets these criteria, with the exception of resolving the nanometer scale liquid film between coalescing bubbles, the code is capable of accurately simulating interface topology changes.

Flow Characteristics of Adiabatic Gas-Liquid Two-Phase Flow in a Horizontal Flat Rectangular Microchannel

2011 ◽  
Author(s):  
Hideo Ide ◽  
Kentaro Satonaka ◽  
Tohru Fukano
Keyword(s):  
Void Fraction ◽  
Slug Flow ◽  
Annular Flow ◽  
Two Phase Flow ◽  
Flow Characteristics ◽  
Flow Patterns ◽  
Phase Flow ◽  
Similar Data ◽  
Two Phase ◽  
The Mean

Experiments were performed to obtain, analyze and clarify the mean void fraction, the mean liquid holdup, and the liquid slug velocity and the air-water two-phase flow patterns in horizontal rectangular microchannels, with the dimensions equal to 1.0 mm width × 0.1 mm depth, and 1.0 mm width × 0.2 mm depth, respectively. The flow patterns such as bubble flow, slug flow and annular flow were observed. The microchannel data showed similar data patterns compared to those in minichannels with the width of 1∼10mm and the depth of 1mm which we had previously reported on. However, in a 1.0 × 0.1 mm microchannel, the mean holdup and the base film thickness in annular flow showed larger values because the effects of liquid viscosity and surface tension on the holdup and void fraction dominate. The remarkable flow characteristics of rivulet flow and the flow with a partial dry out of the channel inner wall were observed in slug flow and annular flow patterns in the microchannel of 0.1 mm depth.

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