An Experimental Investigation of the Thermally Induced Flow Oscillations in Two-Phase Systems

1976 ◽  
Vol 98 (4) ◽  
pp. 616-622 ◽  
Author(s):  
P. Saha ◽  
M. Ishii ◽  
N. Zuber
Keyword(s):  
Experimental Data ◽  
Phase Flow ◽  
Subcooled Boiling ◽  
Two Phase ◽  
Thermally Induced ◽  
System Pressure ◽  
Flow Oscillations ◽  
Induced Flow ◽  
Phase Systems ◽  
Nonequilibrium Theory

An experimental study on the onset of thermally induced two-phase flow oscillations has been carried out in a uniformly heated boiling channel using Freon-113 as the operating fluid. The effects of inlet subcooling, system pressure, inlet and exit restrictions, and inlet velocity have been studied. The experimental data have been compared with the equilibrium as well as the nonequilibrium theory including the effect of subcooled boiling. It has been found that the effect of thermal nonequilibrium should be included in a theoretical model for accurate prediction of the onset and the frequency of thermally induced flow oscillations. A simplified stability criterion has also been presented and compared with the experimental data.

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.

Two-Phase Flow Behavior in Channels With Sudden Area Change Using Experimental and Computational Approach

2017 ◽  
Author(s):  
Ashish Kotwal ◽  
Che-Hao Yang ◽  
Clement Tang
Keyword(s):  
Experimental Data ◽  
Pressure Drop ◽  
Experimental Analysis ◽  
Single Phase ◽  
Computational Analysis ◽  
Phase Flow ◽  
Single Phase Flow ◽  
Two Phase ◽  
Flow Rates ◽  
Area Change

The current study shows computational and experimental analysis of multiphase flows (gas-liquid two-phase flow) in channels with sudden area change. Four test sections used for sudden contraction and expansion of area in experiments and computational analysis. These are 0.5–0.375, 0.5–0.315, 0.5–0.19, 0.5–0.14, inversely true for expansion channels. Liquid Flow rates ranging from 0.005 kg/s to 0.03 kg/s employed, while gas flow rates ranging from 0.00049 kg/s to 0.029 kg/s implemented. First, single-phase flow consists of only water, and second two-phase Nitrogen-Water mixture flow analyzed experimentally and computationally. For Single-phase flow, two mathematical models used for comparison: the two transport equations k-epsilon turbulence model (K-Epsilon), and the five transport equations Reynolds stress turbulence interaction model (RSM). A Eulerian-Eulerian multiphase approach and the RSM mathematical model developed for two-phase gas-liquid flows based on current experimental data. As area changes, the pressure drop observed, which is directly proportional to the Reynolds number. The computational analysis can show precise prediction and a good agreement with experimental data when area ratio and pressure differences are smaller for laminar and turbulent flows in circular geometries. During two-phase flows, the pressure drop generated shows reasonable dependence on void fraction parameter, regardless of numerical analysis and experimental analysis.

Detailed Investigation of Thermal-Hydraulic Aspects During the Reflood Phase in QUENCH Experiments

2004 ◽  
Author(s):  
Christoph Homann ◽  
Wolfgang Hering ◽  
Alexei Miassoedov ◽  
Leo Sepold
Keyword(s):  
Experimental Data ◽  
Two Phase Flow ◽  
Saturation Temperature ◽  
Check Valve ◽  
Material Behavior ◽  
Severe Accident ◽  
Special Importance ◽  
Phase Flow ◽  
Thermal Hydraulics ◽  
Two Phase

The QUENCH program, performed at Forschungszentrum Karlsruhe, Germany, is dedicated to out-of-pile studies of the initiation and progression of damage during core reflood of a degraded commercial nuclear reactor. Main work in this program is spent on the investigation of the material behavior of the solid structures. However, for the deeper understanding of the integral tests, especially of the quench phase, as well as for computational support of the tests and for the validation of severe accident codes, a sufficient knowledge of thermal-hydraulics in the bundle during the quench phase is also mandatory. Though much instrumentation is available in the test section, information to interpret thermal-hydraulics is scare due to principal and technical reasons. The main objective of the present paper is to get a better idea of the reflood process, based on all available experimental data. For this purpose, the test QUENCH-06 is used because of the amount of available qualified experimental data and because of its special importance for code validation, this test being selected as OECD International Standard Problem (ISP) no. 45. At reflood initiation of QUENCH-06, some irregularity of water injection occurred due to the malfunction of a check valve. A thorough inspection and comparison of experimental data is presented in this paper to clarify details of the start of the quench phase. It is complemented by still more detailed computations with the in-house version of SCDAP/RELAP5 mod 3.2 than at the time of ISP-45. Apart from its relevance for this special test and for ISP-45, this work sheds light on the consistency of the involved experimental data. Besides to this investigation, the transition from two- to single-phase flow is examined in more detail than before, giving indications for the axial extension of the two-phase flow region with large droplets or a sensible fluid fraction and for the duration of two-phase flow near saturation temperature. Again, the consistency of data of various instrumentations is assessed. Despite of this success, a better instrumentation for thermal-hydraulics, mainly of void sensors in the lower part of the bundle, is desirable to facilitate interpretation of thermal-hydraulic aspects of the tests.

scholarly journals DILUTE PHASE VERTICAL PNEUMATIC CONVEYING OF CORK STOPPERS

2006 ◽  
Vol 5 (2) ◽  
pp. 36
Author(s):  
R. Barbosa ◽  
C. Pinho
Keyword(s):  
Experimental Data ◽  
Steady State ◽  
Phase Flow ◽  
Pneumatic Conveying ◽  
Simple Correlation ◽  
Two Phase ◽  
State Region ◽  
Single Pipe ◽  
Cork Stoppers

The pneumatic conveying of cork stoppers is used in the cork processingindustries with equipments designed and built purely on an empirical basis.Experimental studies to characterize this type of pneumatic transportationhave been, so far, oriented towards the study of horizontal conveying processes, either for steady state transportation or for the acceleration zone.However studies were carried out on the determination of the pressure dropon vertical transportation of cork stoppers. Here the experimental apparatusand procedure are described, and the first experimental data that have beenobtained are shown. In consequence a simple correlation for the pressure drop in the steady state region of the conveying pipe is proposed. Thecorrelation is a function of dimensionless parameters used to characterizethe two phase flow under analysis. Three standard stoppers sizes and a single pipe diameter were used in the experiments, all carried out at ambient temperature.

Frictional Pressure Losses for Annular Flow of Drilling Mud and Mud-Gas Mixtures

1985 ◽  
Vol 107 (1) ◽  
pp. 142-151 ◽  
Author(s):  
J. P. Langlinais ◽  
A. T. Bourgoyne ◽  
W. R. Holden
Keyword(s):  
Experimental Data ◽  
Single Phase ◽  
Two Phase Flow ◽  
Hydraulic Diameter ◽  
Phase Flow ◽  
Drilling Mud ◽  
Two Phase ◽  
Bingham Plastic ◽  
Pressure Losses ◽  
Annular Geometry

The calculation of single-phase and two-phase flowing pressure gradients in a well annulus is generally based on an extension of empirical correlations developed for Newtonian fluids in circular pipes. Various techniques for extending pipe flow correlations to an annular geometry have been presented in the literature which involve the representation of the annular well geometry with an equivalent circular diameter and the representation of non-Newtonian fluid behavior with an apparent Newtonian viscosity. Unfortunately, little experimental data have been available which would allow a comparison of the relative accuracy of the various proposed techniques. In this study, experimental pressure gradient data have been taken in two 6000-ft wells. Frictional pressure losses for single-phase flow (mud only) in two annuli were compared to values predicted by the Bingham plastic and power law models. These calculations utilized the equivalent diameters defined by the Crittendon criteria, the hydraulic diameter, and the slot approximation. Also, total pressure difference for two-phase flow was measured for one annular geometry. This data was compared to that predicted by the Poettmann and Carpenter, Hagedorn and Brown, Orkiszewski, and Beggs and Brill correlations. Comparison of experimental data with the various prediction techniques was favorable, each having advantage in certain situations. For the data investigated, the Crittendon criteria using a Bingham plastic model gave the best results. The two-phase flow data was best predicted by the Hagedorn and Brown correlation utilizing an equivalent hydraulic diameter.

The Influence of Non-Uniform Heating on Two-Phase Flow Instability in Parallel Channels

2013 ◽  
Author(s):  
Xiaodong Lu ◽  
Linglan Zhou ◽  
Hong Zhang ◽  
Yingwei Wu ◽  
Guanghui Su ◽  
...  
Keyword(s):  
Heat Flux ◽  
Two Phase Flow ◽  
Flow Instability ◽  
System Stability ◽  
System Control ◽  
Phase Flow ◽  
Uniform Heating ◽  
Two Phase ◽  
System Pressure ◽  
Parallel Channels

The two-phase flow instability in parallel channels heated by uniform and non-uniform heat flux has been theoretically studied in this paper. Based on the homogeneous flow model in two-phase region, the system control equations of parallel channels were established. Semi-implicit finite-difference method and staggered mesh method were used to discretize the system control equations and the difference equations were solved with a chasing method. The cosine profile and uniform constant heat flux represent the non-uniform and uniform heating condition, respectively. The marginal stability boundaries (MSB) of parallel channels and the three-dimensional instability spaces (or instability reefs) of different heat flux models were obtained. For cosine profile heating, the stability of parallel channels increases with the increase of the system pressure and inlet resistant coefficient. In high inlet subcooling region, cosine heat flux can strengthen the system stability. However, in low inlet subcooling region, the negative effect to system stability will be caused by non-uniform heating. The increase of inlet resistant coefficient will move the turning point of the MSB to high inlet subcooling number.

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