Experimental Study of Low Concentration Sand Transport in Multiphase Air–Water Horizontal Pipelines

2015 ◽  
Vol 137 (3) ◽  
Author(s):  
Kamyar Najmi ◽  
Alan L. Hill ◽  
Brenton S. McLaury ◽  
Siamack A. Shirazi ◽  
Selen Cremaschi
Keyword(s):  
Experimental Study ◽  
Gas Flow ◽  
Intermittent Flow ◽  
Sand Transport ◽  
Physical Parameters ◽  
Internal Diameter ◽  
Flow Rates ◽  
Minimum Flow ◽  
Wide Range ◽  
Sand Size

The ultimate goal of this work is to determine the minimum flow rates necessary for effective transport of sand in a pipeline carrying multiphase flow. In order to achieve this goal, an experimental study is performed in a horizontal pipeline using water and air as carrier fluids. In this study, successful transport of sand is defined as the minimum flow rates of water and air at which all sand grains continue to move along in the pipe. The obtained data cover a wide range of liquid and gas flow rates including stratified and intermittent flow regimes. The effect of physical parameters such as sand size, sand shape, and sand concentration is experimentally investigated in 0.05 and 0.1 m internal diameter pipes. The comparisons of the obtained data with previous studies show good agreement. It is concluded that the minimum flow rates required to continuously move the sand increases with increasing sand size in the range examined and particle shape does not significantly affect sand transport. Additionally, the data show the minimum required flow rates increase by increasing sand concentration for the low concentrations considered, and this effect should be taken into account in the modeling of multiphase sand transport.

Very Low Concentration Sand Transport in Multiphase Horizontal Pipelines: An Experimental Study and Modeling Guidelines

2015 ◽  
Author(s):  
Kamyar Najmi ◽  
Brenton S. McLaury ◽  
Siamack A. Shirazi ◽  
Selen Cremaschi
Keyword(s):  
Experimental Data ◽  
Particle Interaction ◽  
Operating Conditions ◽  
Sand Transport ◽  
Physical Parameters ◽  
Volume Percent ◽  
Flow Rates ◽  
Low Concentration ◽  
Horizontal Pipes ◽  
Wide Range

Very low concentration sand transport in multiphase horizontal pipes is experimentally investigated in this study. Sand concentration is chosen to be low enough to ignore the effect of particle-particle interaction. This is done to obtain the liquid and gas threshold flow rates which are required to move particles at low concentration (0.002 volume percent) of particles in multiphase pipelines. Along with obtaining the threshold flow rates, the effects of sand concentration, sand size, pipe size and liquid viscosity are also experimentally investigated. Critical velocity is defined to make sure all grains of sand continuously move in the pipe. The experimental data were obtained for a wide range of operating conditions in both intermittent and stratified flow regimes. A comparison of the obtained experimental data in this study with similar studies in the literature reveals the effect of some physical parameters affecting sad transport in multiphase flow pipelines. This study also gives some general guidelines for a more accurate model to predict minimum flow rates to move sand in multiphase flows.

Estimation of Leak Flow Rates Through Narrow Cracks

2009 ◽  
Vol 131 (5) ◽  
Author(s):  
Chungpyo Hong ◽  
Yutaka Asako ◽  
Jae-Heon Lee
Keyword(s):  
Friction Factor ◽  
Gas Flow ◽  
Slip Flow ◽  
Nonlinear Ordinary Differential Equation ◽  
Opening Displacement ◽  
Flow Rates ◽  
Choked Flow ◽  
Runge Kutta Method ◽  
Wide Range ◽  
Leak Before Break

The estimation of the gaseous leak flow rates through a narrow crack is important for a leak-before-break analysis as a method of nondestructive testing. Therefore, the methodology to estimate the gaseous leak flow rates in a narrow crack for a wide range of flow conditions, from no-slip to slip flow and from unchoked to choked flow, by using f⋅Re (the product of friction factor and Reynolds number) correlations obtained for a microchannel, was developed and presented. The correlations applied here were proposed by the previous study (Hong, et al., 2007, “Friction Factor Correlations for Gas Flow in Slip Flow Regime,” ASME J. Fluids Eng., 129, pp. 1268–1276). The detail of the calculation procedure was appropriately documented. The fourth-order Runge–Kutta method was employed to integrate the nonlinear ordinary differential equation for the pressure, and the regular-Falsi method was employed to find the inlet Mach number. An idealized crack, whose opening displacement ranges from 2 μm to 50 μm, with the crack aspect ratio of 200, 1000, and 2000, was chosen for sample estimation. The present results were compared with both numerical simulations and available experimental measurements. The results were in excellent agreement. Therefore, the gaseous leak flow rates can be correctly predicted by using the proposed methodology.

Axial and Radial Investigation of Hydrodynamics in a Bubble Column; Influence of Fluids Flow Rates and Sparger Type

2006 ◽  
Vol 4 (1) ◽  
Author(s):  
Hélène Chaumat ◽  
Anne-Marie Billet ◽  
Henri Delmas
Keyword(s):  
Liquid Flow ◽  
Gas Flow ◽  
Bubble Column ◽  
Bubble Diameter ◽  
Pressure Sensors ◽  
Operating Conditions ◽  
Batch Mode ◽  
Flow Rates ◽  
Wide Range ◽  
Injection Zone

A detailed investigation of local hydrodynamics in a pilot plant bubble column has been performed using various techniques, exploring both axial and radial variations of the gas hold-up, bubble average diameter and frequency, surface area. A wide range of operating conditions has been explored up to large gas and liquid flow rates, with two sparger types. Two main complementary techniques were used: a quasi local measurement of gas hold-up via series of differential pressure sensors to get the axial variation and a double optic probe giving radial variations of gad hold-up, bubble average size and frequency and surface area.According to axial evolutions, three zones, where radial evolutions have been detailed, have been separated: at the bottom the gas injection zone, the large central region or column bulk and the disengagement zone at the column top. It was found that significant axial and radial variations of the two phase flow characteristics do exist even in the so called homogeneous regime. The normalized profiles of bubble frequency appear sparger and gas velocity independent contrary to bubble diameter, gas hold-up and interfacial area normalized profiles. In any case bubbles are larger in the sparger zone than elsewhere.The main result of this work is the very strong effect of liquid flow on bubble column hydrodynamics at low gas flow rate. First the flow regime map observed in batch mode is dramatically modified with a drastic reduction of the homogeneous regime region, up to a complete heterogeneous regime in the working conditions (uG> 0.02 m/s). On the contrary, liquid flow has limited effects at very high gas flow rates.A large data bank is provided to be used for example in detailed comparison with CFD calculations.

scholarly journals KPIM of Gas Transportation: Robust Modification of Gas Pipeline Equations

2008 ◽  
Vol 45 (5) ◽  
pp. 39-47
Author(s):  
A. Falade ◽  
A. Olaberinjo ◽  
M. Oyewola ◽  
F. Babalola ◽  
S. Adaramola
Keyword(s):  
Friction Factor ◽  
Gas Flow ◽  
Research Work ◽  
Flow Equation ◽  
Gas Pipeline ◽  
Flow Rates ◽  
Modified Equations ◽  
Wide Range ◽  
High Degree ◽  
Turbulent Gas Flow

KPIM of Gas Transportation: Robust Modification of Gas Pipeline Equations Studies of the flow conditions of natural gases in pipelines have led to the development of complex equations for relating the volume transmitted through a gas pipeline to the various factors involved, thus deciding the optimum pressures and pipeline dimensions to be used. From equations of this type, various combinations of pipe diameter and wall thickness for a desired rate of gas throughput can be calculated. This research work presents modified forms of the basic gas flow equation for horizontal flow developed by Weymouth and the basic gas flow equation for inclined flow developed by Ferguson. The modified equations incorporate non-iterative forms of the Colebrook-White friction factor into the original forms of the Weymouth's and Ferguson's equations. These modified equations thus eliminate the need for iteration in predicting the flow rate of gas through pipelines as is the case with their original forms when the Colebrook-White friction factor is used. The modified equations also have a wider range of application since the Colebrook-White friction factor is valid for turbulent gas flow as well as for gas flow in a transition zone. On comparing the results it can be seen that the modified Ferguson's equation gives a more accurate prediction of gas flow rates because it takes the pipeline elevation into account. Lower deviations from measured gas flow rates were observed with the modified Ferguson's equation than with the modified basic gas flow equation. The deviations observed using the modified Ferguson equation were found to range from -0.16% to +3.21%. Conclusively, these less cumbersome newly developed equations with high degree reliability will be useful in predicting the rates of gas flow for a wide range of its conditions, pipeline elevation and pipeline lengths.

Development of a Unique, Passive, Microgravity Vortex Separator

2005 ◽  
Author(s):  
M. Ellis ◽  
C. Kurwitz ◽  
F. Best
Keyword(s):  
Waste Water ◽  
Phase Separation ◽  
Power Systems ◽  
Gas Flow ◽  
Full Range ◽  
Operating Conditions ◽  
Microgravity Environment ◽  
Flow Rates ◽  
Wide Range ◽  
Vortex Separator

In the microgravity environment experienced by space vehicles, liquid and gas do not naturally separate as on Earth. This behavior presents a problem for two-phase space systems, such as environment conditioning, waste water processing, and power systems. Furthermore, with recent renewed interest in space nuclear power systems, a microgravity Rankine cycle is attractive for thermal to electric energy conversion and would require a phase separation device. Responding to this need, researchers have conceived various methods of producing phase separation in low gravity environments. These separator types have included wicking, elbow, hydrophobic/hydrophilic, vortex, rotary fan separators, and combinations thereof. Each class of separator achieved acceptable performance for particular applications and most performed in some capacity for the space program. However, increased integration of multiphase systems requires a separator design adaptable to a variety of system operating conditions. To this end, researchers at Texas A&M University (TAMU) have developed a Microgravity Vortex Separator (MVS) capable of handling both a wide range of inlet conditions as well as changes in these conditions with a single, passive design. Currently, rotary separators are recognized as the most versatile microgravity separation technology. However, compared with passive designs, rotary separators suffer from higher power consumption, more complicated mechanical design, and higher maintenance requirements than passive separators. Furthermore, research completed over the past decade has shown the MVS more resistant to inlet flow variations and versatile in application. Most investigations were conducted as part of system integration experiments including, among others, propellant transfer, waste water processing, and fuel cell systems. Testing involved determination of hydrodynamic conditions relating to vortex stability, inlet quality effects, accumulation volume potential, and dynamic volume monitoring. In most cases, a 1.2 liter separator was found to accommodate system flow conditions. This size produced reliable phase separation for liquid flow rates from 1.8 to 9.8 liters per minute, for gas flow rates of 0.5 to 180 standard liters per minute, over the full range of quality, and with fluid inventory changes up to 0.35 liters. Moreover, an acoustic sensor, integrated into the wall of the separation chamber, allows liquid film thickness monitoring with an accuracy of 0.1 inches. Currently, application of the MVS is being extended to cabin air dehumidification and a Rankine power cycle system. Both of these projects will allow further development of the TAMU separator.

Numerical Simulation and Experimental Study of Gas Flow Dynamics in Porous Media: Application in Cold Box Foundry Process

2003 ◽  
Author(s):  
Sayavur I. Bakhtiyarov ◽  
Ruel A. Overfelt
Keyword(s):  
Experimental Study ◽  
Numerical Simulations ◽  
Gas Flow ◽  
Electronic System ◽  
Flow Rates ◽  
Contour Maps ◽  
Pressure Distributions ◽  
Computer Controlled ◽  
Cold Box ◽  
Good Agreement

The results of an experimental study and 3D numerical simulations of resin bonded sand/air flow in a square corebox with an H-shape insertion and passage between upper and lower pockets of the pattern are presented. A computer controlled electronic system was designed and built to measure pressures and flow rates inside the corebox during mold filling, gassing and purging cycles of Phenolic Urethane Amine (PUA) process. Contour maps of the pressure distributions inside the corebox were created based on barometric measurements. A good agreement between experimental results and numerical simulations was found.

Numerical and Experimental Study on Metal Organic Vapor-Phase Epitaxy of InGaN∕GaN Multi-Quantum-Wells

2008 ◽  
Vol 130 (8) ◽  
Author(s):  
Changsung Sean Kim ◽  
Jongpa Hong ◽  
Jihye Shim ◽  
Bum Joon Kim ◽  
Hak-Hwan Kim ◽  
...  
Keyword(s):  
Experimental Study ◽  
Quantum Wells ◽  
Vapor Phase ◽  
Gas Flow ◽  
Vapor Phase Epitaxy ◽  
Operating Conditions ◽  
Cfd Simulations ◽  
Organic Vapor ◽  
Wide Range ◽  
Metal Organic

A numerical and experimental study has been performed to characterize the metal organic vapor-phase epitaxy (MOVPE) growth of InGaN∕GaN multi-quantum-wells. One of the major objectives of the present study is to predict the optimal operating conditions that would be suitable for the fabrication of GaN-based light-emitting diodes using three different reactors, vertical, horizontal, and planetary. Computational fluid dynamics (CFD) simulations considering gas-phase chemical reactions and surface chemistry were carried out and compared with experimental measurements. Through a lot of CFD simulations, the database for the multiparametric dependency of indium incorporation and growth rate in InGaN∕GaN layers has been established in a wide range of growth conditions. Also, a heating system using radio frequency power was verified to obtain the uniform temperature distribution by simulating the electromagnetic field as well as gas flow fields. The present multidisciplinary approach has been applied to the development of a novel-concept MOVPE system as well as performance enhancement of existing commercial reactors.

scholarly journals Statistical Simulation of Non-Circular Cross Section Poiseuille Flows

2003 ◽  
Author(s):  
Jian-Zheng Jiang ◽  
Ching Shen ◽  
Jing Fan
Keyword(s):  
Mass Flow ◽  
Cross Sections ◽  
Lateral Wall ◽  
Physical Parameters ◽  
Height Ratio ◽  
Dsmc Method ◽  
Flow Rates ◽  
Wide Range ◽  
Mass Flow Rates ◽  
Poiseuille Flows

This paper investigates the Poiseuille flows for rectangular, regular hexagonal, and semicircular cross sections in transition regime using particle approaches, namely the direct simulation Monte Carlo (DSMC) method and the information preservation (IP) method. The DSMC and IP results compare well with each other, while the IP method is much more computationally efficient than the DSMC method. The mass flow rates given by IP and DSMC are in agreement with the BGK solutions of Hasegawa and Sone. For rectangular cross sections in the wide range of the width-to-height ratio, the simulation results of the mass flow rates and the velocity profiles along the midperpendicular line have been given for both methods to estimate the lateral wall influence. For the physical quantities, such as the mass flow rate, which are influenced by the whole field, the lateral wall influence must be considered even for width-to-height ratio as large as 10. And for the physical parameters, such as the maximum velocity and the velocity profile along the midperpendicular line, the lateral wall influence can be negligible if the width-to-height ratio is bigger than 5.

scholarly journals Ventilation of window interpane cavity aimed at a higher temperature of the inner pane

2002 ◽  
Vol 6 (1) ◽  
pp. 15-22 ◽  
Author(s):  
Mikhail Diomidov ◽  
Mikhail Nizovtsev ◽  
Viktor Terekhov
Keyword(s):  
Experimental Study ◽  
Heat Flux ◽  
Air Flow ◽  
Winter Season ◽  
Climatic Chamber ◽  
Flow Rates ◽  
Ventilated Cavity ◽  
Wide Range ◽  
Internal Cavities ◽  
Higher Temperature

An experimental study of the thermal performance of an air-flow window with triple glazing is described. The measurements were carried out in a climatic chamber under conditions close to a winter season. In the experiments, the temperature and heat-flux distributions on each pane surface, and also the air-temperature distribution over the window height at the middle of the ventilated cavity were determined. The thermal performances of forced and naturally ventilated windows with internal cavities of various thicknesses are reported for a wide range of air-flow rates.

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