Journal articles: 'Liquid Holdup in Vertical Multiphase Flow'

1

Wang, Dayang, Ningde Jin, Lusheng Zhai, and Yingyu Ren. "Salinity Independent Flow Measurement of Vertical Upward Gas-Liquid Flows in a Small Pipe Using Conductance Method." Sensors 20, no. 18 (September 15, 2020): 5263. http://dx.doi.org/10.3390/s20185263.

Full text

Abstract:

Flow measurement in gas-liquid two-phase flow is always a challenging work, because of the non-uniform phase distribution, severe slippage effect between phases, and different flow structures. Furthermore, the variation of salinity changes the water conductivity, which brings more difficulties to multiphase flow measurement. In this study, a methodology for flow measurement using the conductance method in gas-liquid two-phase flow with salinity change is proposed. The methodology includes the suitable conductivity detection method, the strategy of using combined sensors, and the measurement models of flow parameters. A suitable conductivity detection method that can guarantee that the sensor output is linearly proportional to the conductivity is proposed. This conductivity detection method can ensure that the sensors have a high and constant resolution in the conductivity variation caused by water holdup under the conditions of water conductivity change. Afterward, a combined sensor system consisting of a water holdup sensor, velocity sensor, and water conductivity sensor is designed and experimentally evaluated in gas-water two-phase flow in a 20 mm inner diameter pipe. Considering the non-uniform phase distribution, severe slippage effect between phases, different flow structures, and the variation of salinity, a new water holdup measurement model and flow velocity measurement models are established to achieve salinity independent water holdup measurement and flow velocity measurement for the first time.

APA, Harvard, Vancouver, ISO, and other styles

2

Ren, Guishan, Dangke Ge, Peng Li, Xuemei Chen, Xuhui Zhang, Xiaobing Lu, Kai Sun, Rui Fang, Lifei Mi, and Feng Su. "The Flow Pattern Transition and Water Holdup of Gas–Liquid Flow in the Horizontal and Vertical Sections of a Continuous Transportation Pipe." Water 13, no. 15 (July 30, 2021): 2077. http://dx.doi.org/10.3390/w13152077.

Full text

Abstract:

A series of experiments were conducted to investigate the flow pattern transitions and water holdup during oil–water–gas three-phase flow considering both a horizontal section and a vertical section of a transportation pipe simultaneously. The flowing media were white mineral oil, distilled water, and air. Dimensionless numbers controlling the multiphase flow were deduced to understand the scaling law of the flow process. The oil–water–gas three-phase flow was simplified as the two-phase flow of a gas and liquid mixture. Based on the experimental data, flow pattern maps were constructed in terms of the Reynolds number and the ratio of the superficial velocity of the gas to that of the liquid mixture for different Froude numbers. The original contributions of this work are that the relationship between the transient water holdup and the changes of the flow patterns in a transportation pipe with horizontal and vertical sections is established, providing a basis for judging the flow patterns in pipes in engineering practice. A dimensionless power-law correlation for the water holdup in the vertical section is presented based on the experimental data. The correlation can provide theoretical support for the design of oil and gas transport pipelines in industrial applications.

APA, Harvard, Vancouver, ISO, and other styles

3

Alamu, Mhunir Bayonle. "Gas-Well Liquid Loading Probed With Advanced Instrumentation." SPE Journal 17, no. 01 (January 16, 2012): 251–70. http://dx.doi.org/10.2118/153724-pa.

Full text

Abstract:

Summary Drop size, liquid holdup, and pressure drop have been measured simultaneously in real time. This experiment was carried out with air/water to establish annular two-phase flow on a 0.019-m-internal-diameter vertical pipe (7-m-long multiphase-flow facility). Drop concentration, distribution, and sizes in the core flow were measured using Spraytec, a light-diffraction-based instrumentation. Liquid holdup was logged with pairs of flush-mounted ring-conductance probes at various positions within the test section. Pressure drop was monitored using a differential-pressure meter mounted between two pressure taps separated by a distance of 1.5 m. Subtle changes were observed in the characteristic drop diameters around gas superficial velocities of 21 and 30 m/s following progressive, systematic increase in gas and liquid superficial velocities. The gas superficial velocities at which these changes were observed have been linked with transition boundaries to cocurrent and mist annular flows, respectively. Corresponding similar pseudochanges, fingerprinted in the liquid-holdup and pressure-drop data at these transition boundaries, in addition to film and drop-flow reversals captured on video, make the evidence more compelling. Applicability of core-flow dynamic data to explain various physical processes associated with gas-well liquid loading has been demonstrated.

APA, Harvard, Vancouver, ISO, and other styles

4

Qi, Dan, Honglan Zou, Yunhong Ding, Wei Luo, and Junzheng Yang. "Engineering Simulation Tests on Multiphase Flow in Middle- and High-Yield Slanted Well Bores." Energies 11, no. 10 (September 28, 2018): 2591. http://dx.doi.org/10.3390/en11102591.

Full text

Abstract:

Previous multiphase pipe flow tests have mainly been conducted in horizontal and vertical pipes, with few tests conducted on multiphase pipe flow under different inclined angles. In this study, in light of mid–high yield and highly deviated wells in the Middle East and on the basis of existent multiphase flow pressure research on well bores, multiphase pipe flow tests were conducted under different inclined angles, liquid rates, and gas rates. A pressure prediction model based on Mukherjee model, but with new coefficients and higher accuracy for well bores in the study block, was obtained. It was verified that the newly built pressure drawdown prediction model tallies better with experimental data, with an error of only 11.3%. The effect of inclination, output, and gas rate on the flow pattern, liquid holdup, and friction in the course of multiphase flow were analyzed comprehensively, and six kinds of classical flow regime maps were verified with this model. The results showed that for annular and slug flow, the Mukherjee flow pattern map had a higher accuracy of 100% and 80–100%, respectively. For transition flow, Duns and Ros flow pattern map had a higher accuracy of 46–66%.

APA, Harvard, Vancouver, ISO, and other styles

5

Wordu, David Nwobisi, Felix J. K. Ideriah, and Barinyima Nkoi. "A Study of Pressure Gradient in Multiphase Flow in Vertical Pipes." European Journal of Engineering Research and Science 4, no. 1 (January 23, 2019): 54–59. http://dx.doi.org/10.24018/ejers.2019.4.1.1090.

Full text

Abstract:

The study of multiphase flow in vertical pipes is aimed at effective and accurate design of tubing, surface facilities and well performance optimization for the production of oil and gas in the petroleum industry by developing a better approach for predicting pressure gradient. In this study, field data was analyzed using mathematical model, multiphase flow correlations, statistical model, and computer programming to predict accurately the flow regime, liquid holdup and pressure drop gradient which are important in the optimization of well. A Computer programme was used to prediction pressure drop gradient. Four dimensionless parameters liquid velocity number (Nlv), gas velocity number (Ngv), pipe diameter number (Nd), liquid viscosity number (Nl), were chosen because they represent an integration of the two dominant components that influence pressure drop in pipes. These dominant component are flow channel/media and the flowing fluid. The model was found to give a fit of 100% to the selected data points. Hagedorn & Brown, Griffith &Wallis correlations and model were compared with field data and the overall pressure gradient for a total depth of 10000ft was predicted. The predicted pressure gradient measured was found to be 0.320778psi/ft, Graffith& Wallis gave 0.382649Psi/ft, Hagedorn & Brown gave 0.382649Psi/ft; whereas generated model gave 0.271514Psi/ft. These results indicate that the model equation generated is better and leads to a reasonably accurate prediction of pressure drop gradient according to measured pressure gradient.

APA, Harvard, Vancouver, ISO, and other styles

6

Shynybayeva, Amina, and Luis R. Rojas-Solórzano. "Eulerian–Eulerian Modeling of Multiphase Flow in Horizontal Annuli: Current Limitations and Challenges." Processes 8, no. 11 (November 9, 2020): 1426. http://dx.doi.org/10.3390/pr8111426.

Full text

Abstract:

Multiphase flows are present in many natural phenomena, processing technologies, and industries. In the petroleum industry, the multiphase flow is highly relevant, and special attention is paid to the development of predictive tools that determine flow conditions to guarantee safe and economic hydrocarbon extraction and transportation. Hydrodynamic aspects such as pressure drop and holdup are of primary relevance for the field engineer in daily operations like pumping power calculation and equipment selection and control. Multiphase flow associated with oil production is usually a mixture of liquids and gas. The hydrodynamic behavior has been studied in different pipeline configurations (i.e., vertical ascending/descending and horizontal/inclined pipelines). However, the available information about flow patterns as well as the general conditions present in horizontal annuli is incomplete, even if they are of fundamental relevance in today’s horizontal drilling, production, and well intervention in many oil wells around the world. This review aims to present an in-depth revision of the existing models developed to predict two-phase flow patterns and hydrodynamic conditions in annuli flow, focusing mainly on, but not limited to, horizontal configuration. Key flow parameters and effects caused by annuli geometry and the physical properties of fluids are extensively discussed in the present paper. Different empirical correlations and mechanistic and numerical models on two-phase flow through horizontal/inclined pipelines and in both concentric and eccentric annuli are analyzed. Some of these models partially agree with experimental results and show acceptable predictions of frictional pressure loss and flow patterns. Limitations in current models and challenges to be faced in the next generation of models are also discussed.

APA, Harvard, Vancouver, ISO, and other styles

7

Al-Darmaki, Saeed, Gioia Falcone, Colin Hale, and Geoffrey Hewitt. "Experimental Investigation and Modeling of the Effects of Rising Gas Bubbles in a Closed Pipe." SPE Journal 13, no. 03 (September 1, 2008): 354–65. http://dx.doi.org/10.2118/103129-pa.

Full text

Abstract:

Summary Transient multiphase flow in the wellbore causes problems in well-test interpretation when the well is shut in at surface and the pressure is measured downhole. Pressure-buildup data recorded during a test can be dominated by transient wellbore effects (i.e., phase change, flow reversal, and re-entry of the denser phase into the producing zone), making it difficult to distinguish between true reservoir features and transient wellbore artifacts (Gringarten et al. 2000). This paper is a follow-up to paper SPE 96587 (Ali et al. 2005), which presented experimental results of phase redistribution effects on pressure-buildup data. Though the results of the experiments were revealing, they are complex because they reflect the real well situation. To obtain results in which the phase redistribution in the well is studied independently of the interaction with the reservoir, a further set of experiments was carried out. In these experiments, the tube (simulating the well) was isolated at both the top and the bottom at the same time. The pressure distribution was measured during the transient following shut-in and for the steady-state final condition, in which there was a liquid-filled zone at the bottom of the test section and a gas-filled zone at the top. A substantial number of tests were conducted in the bubbly-flow region and could therefore be analyzed by a simple 1D model for bubbly flow. The results of the comparison between the model and the experimental data are presented in this paper. Introduction In the first study (Ali et al. 2005), experiments were carried out to investigate the effects of wellbore phase redistribution (WPR) and phase re-injection on pressure-buildup data. Single-phase- and two-phase-flow tests were conducted with air and water in the long-tube system (LOTUS) at Imperial College. The LOTUS test layout, as described in paper SPE 96587 (Alii et al. 2005), was designed to simulate a reservoir connected, by a resistance, to the base of a flowing well. The "reservoir" was recreated by a pressurized vessel, while the "well" was simulated by a 10.8-m -long, 32-mm-internal-diameter vertical pipe (i.e., the main LOTUS test section). The well was flowed at controlled rates to mimic those encountered in gas/condensate reservoirs. After steady-state conditions had been attained, the well was shut in at the top of the rig (i.e., at the surface) and the associated transient phenomena were monitored through distributed measurements of pressure, temperature, liquid holdup, and wall shear stress. Pressure-buildup data were interpreted with established well-test-analysis techniques. These initial experiments provided a qualitative and quantitative understanding of the effects of gas rates, liquid rates, and rising gas bubbles on WPR and phase re-injection. Gas flow rate was found to have a higher effect than water flow rate on WPR. This was most probably because of annular flow being the predominant flow regime for the experiments. Phase re-injection was simulated successfully. The lower the reservoir pressure, the higher the liquid re-injection, an analog to low-permeability reservoirs. For a closed system, WPR took place. Rising gas caused an increase in bottomhole pressure. The focus of the second study, presented here, was to investigate WPR independently of the interactions with the reservoir. The LOTUS tube was isolated at both the top and the bottom at the same time. The test section was again the LOTUS 10.8-m-long, 32-mm-internal-diameter vertical tube. A two-phase flow was set up with known air- and water-flow rates. The pressure distribution and void fraction were measured for the steady-state flow, and the flow subsequently was shut down by closing valves at the top and bottom of the test section simultaneously. Although the experiments covered a wide range of conditions, a substantial number of tests were conducted in the bubbly-flow regime. A simple, 1D model for bubbly flow was developed and implemented for comparison with the experimental data. Earlier efforts toward understanding the physics of gas-bubble migration in wells were carried out by Hasan and Kabir (1994; 1993) and Xiao et al. (1996). Aremu (2005) provided an overview of bubbly-flow models applied to the problem of gas kicks while drilling. A detailed review of previously published work on research into transient wellbore phenomena is presented by Falcone (2006). In recent years, much work has been carried out on the phenomena occurring in bubbly flows with a wide range of local measurements, and increasingly, many use computational methods to represent the detailed motions and interfacial deformations of the bubbles.

APA, Harvard, Vancouver, ISO, and other styles

8

Denney, Dennis. "Flow Regimes and Liquid Holdup in Horizontal Multiphase Flow." Journal of Petroleum Technology 53, no. 10 (October 1, 2001): 42. http://dx.doi.org/10.2118/1001-0042-jpt.

Full text

APA, Harvard, Vancouver, ISO, and other styles

9

Tromp, Rutger R., and Lucas M. C. Cerioni. "Multiphase Flow Regime Characterization and Liquid Flow Measurement Using Low-Field Magnetic Resonance Imaging." Molecules 26, no. 11 (June 2, 2021): 3349. http://dx.doi.org/10.3390/molecules26113349.

Full text

Abstract:

Multiphase flow metering with operationally robust, low-cost real-time systems that provide accuracy across a broad range of produced volumes and fluid properties, is a requirement across a range of process industries, particularly those concerning petroleum. Especially the wide variety of multiphase flow profiles that can be encountered in the field provides challenges in terms of metering accuracy. Recently, low-field magnetic resonance (MR) measurement technology has been introduced as a feasible solution for the petroleum industry. In this work, we study two phase air-water horizontal flows using MR technology. We show that low-field MR technology applied to multiphase flow has the capability to measure the instantaneous liquid holdup and liquid flow velocity using a constant gradient low flip angle CPMG (LFA-CPMG) pulse sequence. LFA-CPMG allows representative sampling of the correlations between liquid holdup and liquid flow velocity, which allows multiphase flow profiles to be characterized. Flow measurements based on this method allow liquid flow rate determination with an accuracy that is independent of the multiphase flow profile observed in horizontal pipe flow for a wide dynamic range in terms of the average gas and liquid flow rates.

APA, Harvard, Vancouver, ISO, and other styles

10

Xipeng, Zheng, Wang Le, Jia Xiaoxuan, Xiang Wenchuan, and Yang Shunsheng. "Numerical Simulation of Gas-Liquid Flow in a Bubble Column by Intermittent Aeration in Newtonian Liquid/Non-Newtonian Liquid." International Journal of Chemical Engineering 2018 (November 6, 2018): 1–12. http://dx.doi.org/10.1155/2018/5254087.

Full text

Abstract:

The dynamic behaviors of gas-liquid two-phase flow were simulated in a lab-scale intermittent bubble column by Euler-Euler two-fluid model coupled with the PBM (population balance model) using two different liquid phases, i.e., Newtonian fluid (water)/non-Newtonian fluid (activated sludge). When non-Newtonian fluid was used during intermittent aeration, some interesting results were obtained. Two symmetric vortexes existed in the time-averaged flow field; the vertical time-averaged velocity of the liquid phase decreased with increasing anaerobic time; the average gas holdup distribution was like a trapezoid with long upper side and short lower side and affected by the dynamic viscosity of the liquid phase. Compared with non-Newtonian fluid, the use of Newtonian fluid as the liquid phase led to a more complicated time-averaged flow field structure and vertical time-averaged velocity distribution, higher average gas holdup, and the asymmetric column-shaped gas holdup distribution with increasing anaerobic time. For different liquid phases, the instantaneous flow field, instantaneous vertical velocity, and instantaneous gas holdup distribution all periodically changed with anaerobic time; however, different from Newtonian liquid phase, non-Newtonian liquid phase had no periodic oscillating instantaneous horizontal velocity.

APA, Harvard, Vancouver, ISO, and other styles

11

Fang, Li De, Yu Jiao Liang, Yao Zhang, and Qin He. "Development of Miniature High-Precision Multiphase Flow Simulation Device." Advanced Materials Research 816-817 (September 2013): 656–59. http://dx.doi.org/10.4028/www.scientific.net/amr.816-817.656.

Full text

Abstract:

As the development of petroleum industry, the various fields in the multiphase flow have become the importance research direction of the petroleum industry technology and the interdisciplinary. As a result, it becomes much more necessary for the parameters study such as the measurement of phase holdup to reproduce a variety of flow patterns in laboratory. The paper described one set of miniature high-precision multiphase flow simulation device, which simulated many flow patterns in both horizontal and vertical directions, providing a platform to study the other parameters in the multiphase flow.

APA, Harvard, Vancouver, ISO, and other styles

12

Li, Hong Li, and Yang Dong Li. "Numerical Simulation of Gas-Liquid-Solid Circulating Fluidized Bed (CFB)." Applied Mechanics and Materials 433-435 (October 2013): 1988–91. http://dx.doi.org/10.4028/www.scientific.net/amm.433-435.1988.

Full text

Abstract:

Through summary of multiphase flow coupling, considerate the conservation of mass and momentum conservation, used the gas phase as a continuous phase, liquid phase and solid phase as dispersed phase, CFB has been simulated with the help of Eulerian model. It show that the local gas holdup increases from the computational domain inlet to the outlet, the local solid holdup decreases from the computational domain inlet to the outlet, and the local liquid holdup decreases from the computational domain inlet to the outlet.

APA, Harvard, Vancouver, ISO, and other styles

13

Bello, O. O., K. M. Reinicke, and C. Teodoriu. "Particle Holdup Profiles in Horizontal Gas-liquid-solid Multiphase Flow Pipeline." Chemical Engineering & Technology 28, no. 12 (December 2005): 1546–53. http://dx.doi.org/10.1002/ceat.200500195.

Full text

APA, Harvard, Vancouver, ISO, and other styles

14

Gomez, L. E., O. Shoham, and Y. Taitel. "Prediction of slug liquid holdup: horizontal to upward vertical flow." International Journal of Multiphase Flow 26, no. 3 (March 2000): 517–21. http://dx.doi.org/10.1016/s0301-9322(99)00025-7.

Full text

APA, Harvard, Vancouver, ISO, and other styles

15

An, Hyoung-Jin, Julius P. Langlinais, and S. L. Scott. "Effects of Density and Viscosity in Vertical Zero Net Liquid Flow." Journal of Energy Resources Technology 122, no. 2 (March 3, 2000): 49–55. http://dx.doi.org/10.1115/1.483161.

Full text

Abstract:

An experimental study was conducted to investigate the effects of density and viscosity on zero net liquid flow (ZNLF) in vertical pipes. Predicting liquid holdup under ZNLF conditions is necessary in several types of petroleum industry operations. These include predicting bottomhole pressures in pumping oil wells and the design of compact gas-liquid cylindrical cyclone (GLCC©)1 separators. Models are proposed to predict flow pattern transitions under ZNLF conditions and comparisons are made with commonly used vertical flow pattern transition criteria. Data was collected using a 3-in.-diam, 14-ft-section of transparent vertical pipe. Several different fluids, of differing density and viscosity, were utilized with air flowing at approximately 25 psig. Results are presented showing the liquid holdup and the flow distribution coefficient C0 as a function of density, viscosity, and superficial gas velocity. [S0195-0738(00)00402-7]

APA, Harvard, Vancouver, ISO, and other styles

16

Seong, Yongho, Changhyup Park, Jinho Choi, and Ilsik Jang. "Surrogate Model with a Deep Neural Network to Evaluate Gas–Liquid Flow in a Horizontal Pipe." Energies 13, no. 4 (February 21, 2020): 968. http://dx.doi.org/10.3390/en13040968.

Full text

Abstract:

This study developed a data-driven surrogate model based on a deep neural network (DNN) to evaluate gas–liquid multiphase flow occurring in horizontal pipes. It estimated the liquid holdup and pressure gradient under a slip condition and different flow patterns, i.e., slug, annular, stratified flow, etc. The inputs of the surrogate modelling were related to the fluid properties and the dynamic data, e.g., superficial velocities at the inlet, while the outputs were the liquid holdup and pressure gradient observed at the outlet. The case study determined the optimal number of hidden neurons by considering the processing time and the validation error. A total of 350 experimental data were used: 279 for supervised training, 31 for validating the training performance, and 40 unknown data, not used in training and validation, were examined to forecast the liquid holdup and pressure gradient. The liquid holdups were estimated within less than 8.08% of the mean absolute percentage error, while the error of the pressure gradient was 23.76%. The R2 values confirmed the reliability of the developed model, showing 0.89 for liquid holdups and 0.98 for pressure gradients. The DNN-based surrogate model can be applicable to estimate liquid holdup and pressure gradients in a more realistic manner with a small amount of computating resources.

APA, Harvard, Vancouver, ISO, and other styles

17

Taslim, Taslim, and Mohd Sobri Takriff. "Gas Holdup and Gas-Liquid Mass Transfer Investigations in an Oscillatory Flow in a Baffled Column." ASEAN Journal of Chemical Engineering 2, no. 1 (October 20, 2008): 7. http://dx.doi.org/10.22146/ajche.50797.

Full text

Abstract:

Gas holdup and gas-liquid mass transfer were investigated in a vertical baffled column. Pure carbon dioxide (C02) was used as the dispersed phase and tap water was used as the continuous phase. Gas holdup and mass transfer rate of C02 were measured under semi-batch condition, while the liquid phase was measured in batch mode. Gas holdup was estimated as the volume fraction of the gas in the two-phase mixture in the column. Mass transfer was expressed in terms of the liquid-side volumetric mass transfer coefficient (kLa). The effects of oscillation frequency, oscillation amplitude and gas flow rate on gas holdup andmass transfer were also determined. The results showed that a significant increase in gas holdup and mass transfer could be achieved in an oscillatory baffled column compared to a bubble column. Gas holdup and mass transfer were correlated as a function of power density and superficial gas velocity. Keywords: gas holdup, mass transfer coefficient, power density, superficial gas velocity

APA, Harvard, Vancouver, ISO, and other styles

18

Kaminsky, R. D. "Estimation of Two-Phase Flow Heat Transfer in Pipes." Journal of Energy Resources Technology 121, no. 2 (June 1, 1999): 75–80. http://dx.doi.org/10.1115/1.2795071.

Full text

Abstract:

Heat transfer can be of importance in the design of multiphase petroleum flowlines. However, heat transfer data for gas-liquid flows are available only for small-diameter pipes at low pressures. Moreover, existing prediction methods are largely not suited to petroleum pipeline conditions due to implicit use of simplistic two-phase flow models. In this work heat transfer estimation methods are derived for nonboiling gas-liquid flow in pipes of high Prandtl number liquids, such as crude oil. The methods are readily evaluated for engineering applications and are applicable to all flow regimes, except those with low liquid holdup. Comparison is made with literature data. Accuracies of ±33 percent are obtained in general. The methods explicitly couple with arbitrary prediction methods for two-phase flow pressure drop and liquid holdup. This explicit coupling makes plausible the hypothesis that predictions will be robust at conditions well beyond the range of the existing experimental data.

APA, Harvard, Vancouver, ISO, and other styles

19

Xing, Shi Lu, Zhong Lan Tao, Jian Ming Niu, Rui Tian, and Chun Li Li. "Effect of Aeration Conditions on the Flow Field in the Submerged Membrane Bioreactor." Applied Mechanics and Materials 535 (February 2014): 539–46. http://dx.doi.org/10.4028/www.scientific.net/amm.535.539.

Full text

Abstract:

A full size 3D numerical simulation of gas liquid two-phase flow in a submerged membrane bioreactor was carried out. The standard k-ε turbulence model and Euler multiphase flow model of fluent were used. The effect of changed aeration conditions in the reactor on the gas holdup and gas-liquid velocity distribution in the reactor was studied. The simulation results were shown that, at the same aeration rate, the liquid and gas velocities of 1mm hole aerated at the membrane surface increased faster than 2 mm and 3mm aeration holes; At the same aeration hole , with the increase of aeration rate，the liquid and gas velocities at the membrane surface increased; At the 1mm aeration hole and 5.5m3/h aeration rate, the vortex area was larger and gas holdup was higher, so that gas and liquid were contacting well and the membrane surface scouring effect was better; The Simulation also shown that local gas holdup was lower at close to the wall at the bottom of the reactor, this was not conducive to the growth of microorganisms in the activated sludge, the need to further optimize the structure of aeration and reactor.

APA, Harvard, Vancouver, ISO, and other styles

20

Osman, El-Sayed A. "Artificial Neural Network Models for Identifying Flow Regimes and Predicting Liquid Holdup in Horizontal Multiphase Flow." SPE Production & Facilities 19, no. 01 (February 1, 2004): 33–40. http://dx.doi.org/10.2118/86910-pa.

Full text

APA, Harvard, Vancouver, ISO, and other styles

21

Sayman, Ozan, Eduardo Pereyra, and Cem Sarica. "Comprehensive Fall Velocity Study on Continuous Flow Plungers." SPE Production & Operations 36, no. 03 (May 18, 2021): 604–23. http://dx.doi.org/10.2118/201139-pa.

Full text

Abstract:

Summary The objective of this study is the experimental and theoretical investigation of the fall mechanics of continuous flow plungers. Fall velocity of the two-piece plungers with different sleeve and ball combinations and bypass plungers are examined in both static and dynamic conditions to develop a drag coefficient relationship. The dimensionless analysis conducted included the wall effect, inclination, and the liquid holdup correction of the fall stage. A fall model is developed to estimate fall velocities of the ball, sleeve, and bypass plungers. Sensitivity analysis is performed to reveal influential parameters to the fall velocity of continuous flow plungers. In a static facility, four sleeves with different height, weight, and outer diameter (OD); three balls made with different materials; and a bypass plunger are tested in four different mediums. The wall effect on the settling velocity is defined, and it is used to validate the ball drag coefficient results obtained from the experimental setup. Two-phase flow experiments were conducted by injecting gas into the static liquid column, and the liquid holdup effect on the drag coefficient is observed. Experiments in a dynamic facility are used for liquid holdup and deviation corrections. The fall model is developed to estimate fall velocities of the continuous flow plungers against the flow. Dimensionless parameters obtained in the experiments are combined with multiphase flow simulation to estimate the fall velocity of plungers in the field scale. Reference drag coefficient values of plungers are obtained for respective Reynolds number values. Experimental wall effect, liquid holdup, and inclination corrections are provided. The fall model results for separation time, fall velocity, total fall duration, and maximum flow rate to fall against are estimated for different cases. Sensitivity analysis showed that the drag coefficient, the weight of plungers, pressure, and gas flow rate are the most influential parameters for the fall velocity of the plungers. Furthermore, the fall model revealed that plungers fall slowest at the wellhead conditions for the range of gas flow rates experienced in field conditions. Lower pressure at the wellhead had two opposing effects; namely, reduced gas density, thereby reducing the drag and gas expansion that increased the gas velocity, which in turn increased the drag. Estimating fall velocity of continuous flow plungers is crucial to optimize ball and sleeve separation time, plunger selection, and the gas injection rate for plunger-assisted gas lift (PAGL). The fall model provides maximum flow rate to fall against, which is defined as the upper operational boundary for continuous flow plungers. This study presents a new methodology to predict fall velocity using the drag coefficient vs. Reynolds number relationship, wall effect, liquid holdup, deviation corrections, and incorporating multiphase flow simulation.

APA, Harvard, Vancouver, ISO, and other styles

22

Wang, Sheng, He Dong, Zhongfeng Geng, and Xiuqin Dong. "CFD Study of Gas Holdup and Frictional Pressure Drop of Vertical Riser Inside IC Reactor." Processes 7, no. 12 (December 9, 2019): 936. http://dx.doi.org/10.3390/pr7120936.

Full text

Abstract:

The internal circulation system in Internal Circulation (IC) reactor plays an important role in increasing volumetric loading rate and promoting the mixing between sludge and wastewater. In order to design the internal circulation system, the flow behaviors of gas-liquid inside vertical riser should be studied in detail. In the present study, the Multiple Flow Regimes model is adopted to capture the phase interface for different flow conditions. The flow patterns, internal circulation flow rate, gas holdup, and frictional pressure drop of vertical riser are investigated. The results show that the bubble flow inside a vertical riser is in a stable flow condition. There exists a maximum value for internal circulation flow rate with the increasing superficial gas velocity. The parameters of Martinelli models for gas holdup and frictional pressure drop are improved based on Computational Fluid Dynamics (CFD) results. The deviations between the calculated gas holdup and frictional pressure drop by improved model and experimental value are reduced to 14% and 13.2%, respectively. The improved gas holdup and frictional pressure drop model can be used for the optimal design of internal circulation system.

APA, Harvard, Vancouver, ISO, and other styles

23

Xiao, J. J., and G. Shoup. "Sizing Wet-Gas Pipelines and Slug Catchers With Steady-State Multiphase Flow Simulations." Journal of Energy Resources Technology 120, no. 2 (June 1, 1998): 106–10. http://dx.doi.org/10.1115/1.2795019.

Full text

Abstract:

The design of wet-gas pipelines and slug catchers requires multiphase flow simulations, both steady-state and transient. However, steady-state simulation is often inadequately conducted and its potential not fully utilized. This paper shows how mechanistic steady-state simulation models can be used to obtain not only pressure drop, liquid holdup and flow regime, but also to extract important operational information such as pig transit time, pig exit speed, liquid buildup rate behind the pig, and the time for the pipeline to return to a steady-state after pigging. A well-designed set of steady-state simulations helps to determine pipeline size, slug catcher size, and pigging frequency. It also serves as a starting point for subsequent transient multiphase flow simulations.

APA, Harvard, Vancouver, ISO, and other styles

24

Wang, Wei Qiang, Kai Feng Fan, Yu Fei Wan, Ming Wu, and Le Yang. "Study on the Pigging Process of Rich Gas Pipeline." Advanced Materials Research 884-885 (January 2014): 242–46. http://dx.doi.org/10.4028/www.scientific.net/amr.884-885.242.

Full text

Abstract:

Intensive study on flowing properties of two-phase fluid of gas and liquid during pipeline pigging helps to improve the safety operation of rich gas pipeline. Therefore, based on the multiphase fluid transient simulation software, a two-fluid model is employed to study the flowing regulation of gas and liquid in practical operation of natural gas pipeline pigging,especially the change rule of velocity,flow pattern, pressure, liquid holdup ratio, and liquid slug in the passing ball process. The results reveal that three flow patterns appeared in pipeline pigging. They are stratified flow, slug flow and bubble flow. The place where the particular flow pattern appears is related to the terrain. The biggest pressure is found at the entrance, then pressure comes down along the pipeline, and fluctuate according to the fluid amount and terrain; the transient velocity of pig is coherent with the terrain and liquid holdup ratio; small slug flows are easy to gather and form into a longer one. The research can somehow guide to the safety operation of natural gas pipeline pigging.

APA, Harvard, Vancouver, ISO, and other styles

25

El-Sebakhy, Emad A. "Flow regimes identification and liquid-holdup prediction in horizontal multiphase flow based on neuro-fuzzy inference systems." Mathematics and Computers in Simulation 80, no. 9 (May 2010): 1854–66. http://dx.doi.org/10.1016/j.matcom.2010.01.002.

Full text

APA, Harvard, Vancouver, ISO, and other styles

26

Abd Halim, Nur Khairunnisa, and Siti Aslina Hussain. "CFD Analysis of Phase Holdup Behaviour in a Gas-Liquid Bubble Column." Journal of Applied Science & Process Engineering 8, no. 1 (April 30, 2021): 738–49. http://dx.doi.org/10.33736/jaspe.3180.2021.

Full text

Abstract:

Experimental works on bubble column hydrodynamic are normally carried out on a laboratory scale less than 0.3 m with holes number less than 10. In this paper, we discuss several approaches to bubble column scale-up, relying on variables of parameters. Two spargers with different hole diameters (0.5 mm and 1.25 mm) and superficial gas velocities (0.0125 m/s and 0.0501 m/s) are used to determine the distribution of gas holdup and liquid flow pattern. An Insignificant level of bed heights is investigated for the efficiency of hydrodynamic performance. Computational Fluid Dynamic (CFD) is used as the realistic representation of the actual reactor. The flow of the gas-liquid interface is implemented using the VOF model using the finite volume method by tracking the volume fraction of each of the fluids throughout the domain. It is observed that the initial bed heights, superficial gas velocity, and hole diameter of the sparger influence the overall gas holdup. Although the difference in sparger hole diameter affects overall gas holdup, the results are weak relative to other operating conditions. The simulation work is then compared with experimental data to improve the accuracy in analyzing the hydrodynamics of multiphase system, as well as validated the multidimensional models.

APA, Harvard, Vancouver, ISO, and other styles

27

Al-Ruhaimani, Feras, Eduardo Pereyra, Cem Sarica, Eissa Al-Safran, and Carlos Torres. "Prediction of Slug-Liquid Holdup for High-Viscosity Oils in Upward Gas/Liquid Vertical-Pipe Flow." SPE Production & Operations 33, no. 02 (May 1, 2018): 281–99. http://dx.doi.org/10.2118/187957-pa.

Full text

APA, Harvard, Vancouver, ISO, and other styles

28

Shirdel, Mahdy, and Kamy Sepehrnoori. "Development of a Transient Mechanistic Two-Phase Flow Model for Wellbores." SPE Journal 17, no. 03 (September 4, 2012): 942–55. http://dx.doi.org/10.2118/142224-pa.

Full text

Abstract:

Summary A great deal of research has been focused on transient two-phase flow in wellbores. However, there is lack of a comprehensive two-fluid model in the literature. In this paper, we present an implementation of a pseudo-compositional, thermal, fully implicit, transient two-fluid model for two-phase flow in wellbores. In this model, we solve gas/liquid mass balance, gas/liquid momentum balance, and two-phase energy balance equations to obtain five primary variables: liquid velocity, gas velocity, pressure, holdup, and temperature. This simulator can be used as a stand-alone code or can be used in conjunction with a reservoir simulator to mimic wellbore/reservoir dynamic interactions. In our model, we consider stratified, bubbly, intermittent, and annular flow regimes using appropriate closure relations for interphase and wall-shear stress terms in the momentum equations. In our simulation, we found that the interphase and wall-shear stress terms for different flow regimes can significantly affect the model's results. In addition, the interphase momentum transfer terms mainly influence the holdup value. The outcome of this research leads to a more accurate simulation of multiphase flow in the wellbore and pipes, which can be applied to the surface facility design, well-performance optimization, and wellbore damage estimation.

APA, Harvard, Vancouver, ISO, and other styles

29

Biswas, A. B., and S. K. Das. "Holdup Characteristics of Gas-Non-Newtonian Liquid Flow through Helical Coils in Vertical Orientation." Industrial & Engineering Chemistry Research 45, no. 25 (December 2006): 8748. http://dx.doi.org/10.1021/ie068011+.

Full text

APA, Harvard, Vancouver, ISO, and other styles

30

Biswas, A. B., and S. K. Das. "Holdup Characteristics of Gas−Non-Newtonian Liquid Flow through Helical Coils in Vertical Orientation." Industrial & Engineering Chemistry Research 45, no. 21 (October 2006): 7287–92. http://dx.doi.org/10.1021/ie060420i.

Full text

APA, Harvard, Vancouver, ISO, and other styles

31

Al-Safran, Eissa, Mohammad Ghasemi, and Feras Al-Ruhaimani. "High-Viscosity Liquid/Gas Flow Pattern Transitions in Upward Vertical Pipe Flow." SPE Journal 25, no. 03 (February 19, 2020): 1155–73. http://dx.doi.org/10.2118/199901-pa.

Full text

Abstract:

Summary High-viscosity liquid two-phase upward vertical flow in wells and risers presents a new challenge for predicting pressure gradient and liquid holdup due to the poor understanding and prediction of flow pattern. The objective of this study is to investigate the effect of liquid viscosity on two-phase flow pattern in vertical pipe flow. Further objective is to develop new/improve existing mechanistic flow-pattern transition models for high-viscosity liquid two-phase-flow vertical pipes. High-viscosity liquid flow pattern two-phase flow data were collected from open literature, against which existing flow-pattern transition models were evaluated to identify discrepancies and potential improvements. The evaluation revealed that existing flow transition models do not capture the effect of liquid viscosity, resulting in poor prediction. Therefore, two bubble flow (BL)/dispersed bubble flow (DB) pattern transitions are proposed in this study for two different ranges of liquid viscosity. The first proposed transition model modifies Brodkey's critical bubble diameter (Brodkey 1967) by including liquid viscosity, which is applicable for liquid viscosity up to 100 mPa·s. The second model, which is applicable for liquid viscosities above 100 mPa·s, proposes a new critical bubble diameter on the basis of Galileo's dimensionless number. Furthermore, the existing bubbly/intermittent flow (INT) transition model on the basis of a critical gas void fraction of 0.25 (Taitel et al. 1980) is modified to account for liquid viscosity. For the INT/annular flow (AN) transition, the Wallis transition model (Wallis 1969) was evaluated and found to be able to predict the high-viscosity liquid flow pattern data more accurately than the existing models. A validation study of the proposed transition models against the entire high-viscosity liquid experimental data set revealed a significant improvement with an average error of 22.6%. Specifically, the model over-performed existing models in BL/INT and INT/AN pattern transitions.

APA, Harvard, Vancouver, ISO, and other styles

32

Liu, Zilong, Yubin Su, Ming Lu, Zilong Zheng, and Ruiquan Liao. "Frictional Pressure Drop and Liquid Holdup of Churn Flow in Vertical Pipes with Different Viscosities." Geofluids 2021 (January 26, 2021): 1–8. http://dx.doi.org/10.1155/2021/6661014.

Full text

Abstract:

Churn flow commonly exists in the pipe of heavy oil, and the characteristics of churn flow should be widely understood. In this paper, we carried out air and viscous oil two-phase flow experiments, and the diameter of the test section is 60 mm. The viscosity range of the oil was 100~480 mPa·s. Based on the measured liquid holdup and pressure drop data of churn flow, it can be concluded that, due to the existence of liquid film backflow, positive and negative frictional pressure drop can be found and the change of frictional pressure drop with the superficial gas velocity is related to superficial liquid velocity. With the increase of viscosity, the change rate of frictional pressure drop increases with the increase of the superficial gas velocity. Combining our previous work and the Taitel model, we proposed a new pressure drop model for viscous oil-air two-phase churn flow in vertical pipes. By comparing the predicted values of existing models with the measured pressure drop data, the proposed model has better performance in predicting the pressure drop.

APA, Harvard, Vancouver, ISO, and other styles

33

Liu, Zilong, Ruiquan Liao, Wei Luo, Yubin Su, and Joseph X. F. Ribeiro. "A New Model for Predicting Slug Flow Liquid Holdup in Vertical Pipes with Different Viscosities." Arabian Journal for Science and Engineering 45, no. 9 (February 4, 2020): 7741–50. http://dx.doi.org/10.1007/s13369-019-04308-5.

Full text

APA, Harvard, Vancouver, ISO, and other styles

34

Hu, Xiaofei, Aziz Dogan Ilgun, Alberto Passalacqua, Rodney O. Fox, Francesco Bertola, Miran Milosevic, and Frans Visscher. "CFD simulations of stirred-tank reactors for gas-liquid and gas-liquid-solid systems using OpenFOAM®." International Journal of Chemical Reactor Engineering 19, no. 2 (February 1, 2021): 193–207. http://dx.doi.org/10.1515/ijcre-2019-0229.

Full text

Abstract:

Abstract An open-source CFD software OpenFOAM® is used to simulate two multiphase stirred-tank reactors relevant to industrial processes such as slurry polymerization and fuel production. Gas-liquid simulations are first performed in a single-impeller stirred-tank reactor, studied experimentally by Ford, J. J., T. J. Heindel, T. C. Jensen, and J. B. Drake. 2008. “X-Ray Computed Tomography of a Gas-Sparged Stirred-Tank Reactor.” Chemical Engineering Science 63: 2075–85. Three impeller rotation speeds (200, 350 and 700 rpm) with three different bubble diameters (0.5, 1.5 and 2.5 mm) are investigated. Flow patterns compared qualitatively to those from experiments. Compared to the experimental data, the simulations are in relatively good agreement for gas holdup in the reactor. The second multiphase system is a multi-impeller stirred-tank reactor, studied experimentally by Shewale, S. D., and A. B. Pandit. 2006. “Studies in Multiple Impeller Agitated Gas-Liquid Contractors.” Chemical Engineering Science 61: 486–504. Gas-liquid simulations are performed at two impeller rotation speeds (3.75 and 5.08 RPS). The simulated flow patterns agree with published pictures from the experiments. Gas-liquid-solid simulations of the multi-impeller stirred-tank reactor are also carried out at impeller rotation speed 5.08 RPS. The addition of solid particles with a volume fraction characteristic of slurry reactors changes the flow pattern significantly. The bottom Rushton turbine becomes flooded, while the upper pitched-blade downflow turbines present a radial-pumping flow pattern instead of down-pumping. Nonetheless, the solid phase has a similar flow pattern to the liquid phase, indicating that the particles modify the effective density of the fluid.

APA, Harvard, Vancouver, ISO, and other styles

35

Bar, Nirjhar, and Sudip Kumar Das. "Modeling of Gas Holdup and Pressure Drop Using ANN for Gas-Non-Newtonian Liquid Flow in Vertical Pipe." Advanced Materials Research 917 (June 2014): 244–56. http://dx.doi.org/10.4028/www.scientific.net/amr.917.244.

Full text

Abstract:

This paper is an attempt to compare the the performance of the three different Multilayer Perceptron training algorithms namely Backpropagation, Scaled Conjugate Gradient and Levenberg-Marquardt for the prediction of the gas hold up and frictional pressure drop across the vertical pipe for gas non-Newtonian liquid flow from our earlier experimental data. The Multilayer Perceptron consists of a single hidden layer. Four different transfer functions were used in the hidden layer. All three algorithms were useful to predict the gas holdup and frictional pressure drop across the vertical pipe. Statistical analysis using Chi-square test (χ2) confirms that the Backpropagation training algorithm gives the best predictability for both cases.

APA, Harvard, Vancouver, ISO, and other styles

36

Felizola, H., and O. Shoham. "A Unified Model for Slug Flow in Upward Inclined Pipes." Journal of Energy Resources Technology 117, no. 1 (March 1, 1995): 7–12. http://dx.doi.org/10.1115/1.2835324.

Full text

Abstract:

The effect of pipe inclination on upward two-phase slug flow characteristics has been studied both experimentally and theoretically. Experimental data were acquired for the entire range of inclination angles, from horizontal to vertical. New correlations were developed for slug length and liquid holdup in the slug body as a function of inclination angle. A unified model has been developed for the prediction of slug flow behavior in upward inclined pipes. Reasonable agreement is observed between the pressure drop predicted by the model and the experimental data.

APA, Harvard, Vancouver, ISO, and other styles

37

Caetano, E. F., O. Shoham, and J. P. Brill. "Upward Vertical Two-Phase Flow Through an Annulus—Part II: Modeling Bubble, Slug, and Annular Flow." Journal of Energy Resources Technology 114, no. 1 (March 1, 1992): 14–30. http://dx.doi.org/10.1115/1.2905916.

Full text

Abstract:

Mechanistic models have been developed for each of the existing two-phase flow patterns in an annulus, namely bubble flow, dispersed bubble flow, slug flow, and annular flow. These models are based on two-phase flow physical phenomena and incorporate annulus characteristics such as casing and tubing diameters and degree of eccentricity. The models also apply the new predictive means for friction factor and Taylor bubble rise velocity presented in Part I. Given a set of flow conditions, the existing flow pattern in the system can be predicted. The developed models are applied next for predicting the flow behavior, including the average volumetric liquid holdup and the average total pressure gradient for the existing flow pattern. In general, good agreement was observed between the experimental data and model predictions.

APA, Harvard, Vancouver, ISO, and other styles

38

Das, S. K., M. N. Biswas, and A. K. Mitra. "Holdup for two-phase flow of gas-non-newtonian liquid mixtures in horizontal and vertical pipes." Canadian Journal of Chemical Engineering 70, no. 3 (June 1992): 431–37. http://dx.doi.org/10.1002/cjce.5450700304.

Full text

APA, Harvard, Vancouver, ISO, and other styles

39

Voutsinas, Alexandros, Toshihiko Shakouchi, Junichi Takamura, Koichi Tsujimoto, and Toshitake Ando. "FLOW AND CONTROL OF VERTICAL UPWARD GAS-LIQUID TWO-PHASE FLOW THROUGH SUDDEN CONTRACTION PIPE(Multiphase Flow 2)." Proceedings of the International Conference on Jets, Wakes and Separated Flows (ICJWSF) 2005 (2005): 307–12. http://dx.doi.org/10.1299/jsmeicjwsf.2005.307.

Full text

APA, Harvard, Vancouver, ISO, and other styles

40

Messilem, Abdelkader, Abdelwahid Azzi, Ammar Zeghloul, Faiza Saidj, Hiba Bouyahiaoui, and Al-Sarkhi Abdelsalam. "Single- and two-phase pressure drop through vertical Venturis." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 234, no. 12 (February 11, 2020): 2349–59. http://dx.doi.org/10.1177/0954406220906424.

Full text

Abstract:

An experimental investigation of the pressure drops measurements in a Venturi placed in a vertical pipe is achieved. Venturis with diameter ratios equal to 0.4, 0.55, and 0.75 were employed. Differential pressure transducers were used to measure the pressure drop between the Venturi inlet and the throat sections. The void fraction was measured upstream the Venturi using a conductance probe technique. Air and water superficial velocities ranges were chosen to cover single-phase flow and bubbly, slug, and churn flow regimes. The single-phase pressure drop increases with the liquid superficial velocity. The Venturi pressure drop coefficient increases with decreasing the Venturi area ratio. The discharge coefficient increases slightly with this ratio and approaches a value of unity at high Reynolds number. The two-phase flow pressure drop and the multiplier coefficient increase with the gas superficial velocity and with decreasing the area ratio. Dimensionless pressure drop decreases with increasing the liquid to gas superficial velocity ratio and approaches an asymptotic value at high ratio (greater than 10). This value matches the single-phase flow dimensionless pressure drop value at high Reynolds number. The Venturi with area ratio equal to 0.55 was shown to correlate well the two-phase multiplier and the liquid holdup.

APA, Harvard, Vancouver, ISO, and other styles

41

Tatulcenkovs, Andrejs, Andris Jakovics, Egbert Baake, and Bernard Nacke. "Lattice Boltzmann modelling for multiphase bubble flow in electroconducting liquids." COMPEL - The international journal for computation and mathematics in electrical and electronic engineering 36, no. 2 (March 6, 2017): 401–7. http://dx.doi.org/10.1108/compel-05-2016-0224.

Full text

Abstract:

Purpose The purpose of this paper is to the study the multiphase bubbles flow motion in a vertical channel with an electroconducting liquid without and under the influence of a magnetic field. Design/methodology/approach For numerical calculations, the lattice Boltzmann method (LBM) is used, which is based on the kinetic theory for solving fluid mechanics and other physical problems. The phase-field lattice Boltzmann model is developed to simulate the behaviour of multiphase bubble–bubble interaction while rising in the fluid with high density ratios. Findings The behaviour of the rising bubble flow in a rectangular column of two phases is investigated with the two-dimensional LBM. Originality/value The multiphase flow in electroconducting liquids with high ratio of density is studied using the LBM.

APA, Harvard, Vancouver, ISO, and other styles

42

Brandt, Agata, Krystian Czernek, Małgorzata Płaczek, and Stanisław Witczak. "Downward Annular Flow of Air–Oil–Water Mixture in a Vertical Pipe." Energies 14, no. 1 (December 23, 2020): 30. http://dx.doi.org/10.3390/en14010030.

Full text

Abstract:

The paper presents the results of a study concerned with the hydrodynamics of an annular downward multiphase flow of gas and two mutually non-mixing liquids through a vertical pipe with a diameter of 12.5 mm. The air, oil and water were used as working media in this study with changes in superficial velocities in the ranges of jg = 0.34–52.5 m/s for air, jo = 0.000165–0.75 m/s for oil, and jw = 0.02–2.5 m/s for water, respectively. The oil density and viscosity were varied within the ranges of ρo = 859–881 kg/m3 and ηo = 29–2190 mPas, respectively. The research involved the identification of multiphase flow patterns and determination of the void fraction of the individual phases. New flow patterns have been identified and described for the gravitational flow conditions of a two-phase water–oil liquid and a three-phase air–water–oil flow. New flow regime maps and equations for the calculation of air, oil and water void fractions have been developed. A good conformity between the calculated and measured values of void fraction were obtained. The map for the oil–water–air three-phase flow is valid for the following conditions: j3P = 0.35–53.4 m/s (velocity of three-phase mixture) and oil in liquid concentration βo* = 0.48–94% (oil in liquid concentration). In the case of a downward annular oil–water two-phase flow, this map is valid for liquid mixture velocity jl = 0.052–2.14 m/s and βo* = 0.48–94%.

APA, Harvard, Vancouver, ISO, and other styles

43

Janecki, Daniel, Andrzej Burghardt, and Grażyna Bartelmus. "Parametric sensitivity of a CFD model concerning the hydrodynamics of trickle-bed reactor (TBR)." Chemical and Process Engineering 37, no. 1 (March 1, 2016): 97–107. http://dx.doi.org/10.1515/cpe-2016-0010.

Full text

Abstract:

Abstract The aim of the present study was to investigate the sensitivity of a multiphase Eulerian CFD model with respect to relations defining drag forces between phases. The mean relative error as well as standard deviation of experimental and computed values of pressure gradient and average liquid holdup were used as validation criteria of the model. Comparative basis for simulations was our own data-base obtained in experiments carried out in a TBR operating at a co-current downward gas and liquid flow. Estimated errors showed that the classical equations of Attou et al. (1999) defining the friction factors Fjk approximate experimental values of hydrodynamic parameters with the best agreement. Taking this into account one can recommend to apply chosen equations in the momentum balances of TBR.

APA, Harvard, Vancouver, ISO, and other styles

44

Caetano, E. F., O. Shoham, and J. P. Brill. "Upward Vertical Two-Phase Flow Through an Annulus—Part I: Single-Phase Friction Factor, Taylor Bubble Rise Velocity, and Flow Pattern Prediction." Journal of Energy Resources Technology 114, no. 1 (March 1, 1992): 1–13. http://dx.doi.org/10.1115/1.2905917.

Full text

Abstract:

Upward gas-liquid flow through vertical concentric and fully eccentric annuli was studied both experimentally and theoretically. A flow system was designed and constructed for this study. The system consists of a 16-m long vertical annulus with 76.2-mm i.d. casing and 42.2-mm o.d. tubing. A comprehensive experimental investigation was conducted for both concentric and fully eccentric annuli configurations, using air-water and air-kerosene mixtures as the flowing fluids. Included were definition and classification of the existing flow patterns and development of flow pattern maps. Measurements of volumetric average liquid holdup and average total pressure gradient were made for each flow pattern for a wide range of flow conditions. Additional data include single-phase friction factor values and Taylor bubble rise velocities in a stagnant liquid column. Data analysis revealed that application of the hydraulic diameter concept for annuli configurations is not always adequate, especially at low Reynolds number flow conditions. A more rigorous approach was thus required for accurate prediction of the flow behavior, especially for two-phase flow. Part I of the study includes experimental data and analyses of single-phase friction factor, Taylor bubble rise velocity, and flow pattern transition boundaries.

APA, Harvard, Vancouver, ISO, and other styles

45

Zhang, Junping, Norman Epstein, John R. Grace, and Kokseng Lim. "Bubble Characteristics in a Developing Vertical Gas–Liquid Upflow Using a Conductivity Probe." Journal of Fluids Engineering 122, no. 1 (October 12, 1999): 138–45. http://dx.doi.org/10.1115/1.483250.

Full text

Abstract:

Experiments were carried out in an 82.6-mm-dia column with a perforated distributor plate. Conductivity probes on the axis of the column were used to measure local bubble properties in the developing flow region for superficial air velocities from 0.0018 to 6.8 m/s and superficial water velocities from 0 to 0.4 m/s, corresponding to the discrete bubble, dispersed bubble, coalesced bubble, slug, churn, bridging, and annular flow regimes. Bubble frequency increased linearly with gas velocity in the discrete and dispersed bubble regimes. Bubble frequency also increased with gas velocity in the slug flow regime, but decreased in the churn and bridging regimes. Bubble chord length and its distribution were smaller and narrower in the dispersed than in the discrete bubble regime. Both the average and standard deviation of the bubble chord length increased with gas velocity in the discrete, dispersed, and churn flow regimes. However, the average bubble chord length did not change significantly in the slug flow regime due to the high population of small bubbles in the liquid plugs separating Taylor bubbles. The bubble travel length, defined as the product of local gas holdup and local bubble velocity divided by local bubble/void frequency, is used to correlate bubble characteristics and to characterize the flow regimes. [S0098-2202(00)00101-2]

APA, Harvard, Vancouver, ISO, and other styles

46

Giwa, Abdulwahab, Abdulkabir Olawale Gidado, and John Olusoji Owolabi. "Sensitivity Analysis of Multiphase Flow in a well Using PROSPER." International Journal of Engineering Research in Africa 49 (June 2020): 39–53. http://dx.doi.org/10.4028/www.scientific.net/jera.49.39.

Full text

Abstract:

Pressure drop in a vertical or deviated borehole has been found to be due to hydrostatic changes and friction as a result of the produced fluids flowing to the surface. When oil flows upwards, the flowing pressure along the tubing string drops, and this makes gas to start liberating. Thus, multiphase flow forms in the tubing string. Hence, adequate modelling of vertical lift performance is required to predict the pressure drop and subsequently the wellbore pressure because many factors are involved [1]. In this work, sensitivity analysis of multiphase flow in a well has been carried out with the aid of PROSPER in which the most accurate correlation was chosen from twelve selected built-in correlations present in the program to predict the pressure drop via gradient matching. A sensitivity analysis of the well was further performed to investigate the parameters such as tubing diameter, gas-oil ratio and wellhead pressure that were affecting the vertical lift performance of a high water cut well. The results obtained from the correlation matching showed that Dun and Ros [2] original correlation was the best fit correlation for the well. The results of the sensitivity analysis revealed that reduction of wellhead pressure from 600 psi to 400 psi could increase liquid rate by 41%. An adjustment of wellhead pressure was found to give the most significant impact on the production rate of the well as compared to other two parameters studied.

APA, Harvard, Vancouver, ISO, and other styles

47

Wong, Chong Yau, Joan Boulanger, and Gregory Short. "Modelling the Effect of Particle Size Distribution in Multiphase Flows with Computational Fluid Dynamics and Physical Erosion Experiments." Advanced Materials Research 891-892 (March 2014): 1615–20. http://dx.doi.org/10.4028/www.scientific.net/amr.891-892.1615.

Full text

Abstract:

It is known that particle size has an influence in determining the erosion rate, and hence equipment life, on a target material in single phase flows (i.e. flow of solid particles in liquid only or gas only flows). In reality single phase flow is rarely the case for field applications in the oil and gas industry. Field cases are typically multiphase in nature, with volumetric combinations of gas, liquid and sand. Erosion predictions of multiphase flows extrapolated from single phase flow results may be overly conservative. Current understanding of particle size distribution on material erosion in multiphase flows is limited. This work examines the effect of particle size distribution on material erosion of a cylindrical aluminium rod positioned in a 2" vertical pipe under slug and distributed bubble regimes using various water and air volume ratios. This is achieved through physical erosion experiments and computational fluid dynamics (CFD) simulations tailored to account for particle dynamics in multiphase flows.

APA, Harvard, Vancouver, ISO, and other styles

48

Shang, Li Yan, Shan Lin Zhao, Zhen Pan, and Teng Long Huang. "Study on Kinetic Characteristics of Solid-Liquid Two-Phase in Transporting Pipeline of Natural Gas Hydrate." Advanced Materials Research 881-883 (January 2014): 1814–18. http://dx.doi.org/10.4028/www.scientific.net/amr.881-883.1814.

Full text

Abstract:

Based on multiphase flow theory and calculation method, the distribution of internal multiphase flow field in the vertical rise pipeline of natural gas hydrate is simulated with FLUENT as a tool and the mixture of natural gas hydrate solid particles and water as a medium. The change rules of velocity field and volume concentration field are described and the effect of solid particles diameter, density and volume concentration of the natural gas hydrate on the pressure loss and resistance loss of pipeline is also analyzed deeply. It provides theoretical basis on transporting of natural gas hydrate solid particles by pipeline. Keywords:natural gas hydrate. pipeline. solid-liquid two-phase flow. kinetic characteristic. numerical simulation.

APA, Harvard, Vancouver, ISO, and other styles

49

Al-Ruhaimani, F., E. Pereyra, C. Sarica, E. M. Al-Safran, and C. F. Torres. "Experimental Analysis and Model Evaluation of High-Liquid-Viscosity Two-Phase Upward Vertical Pipe Flow." SPE Journal 22, no. 03 (November 18, 2016): 712–35. http://dx.doi.org/10.2118/184401-pa.

Full text

Abstract:

Summary Understanding the behavior of two-phase flow is a key parameter for a proper oil/gas-production-system design. Mechanistic models have been developed and tuned to model the entire production system. Most existing two-phase-flow models are derived from experimental data with low-viscosity liquids (μL < 20 mPa·s). However, behavior of two-phase flow is expected to be significantly different for high-viscosity oil. The effect of high liquid viscosity on two-phase flow is still not well-studied in vertical pipes. In this study, the effect of high oil viscosity on upward two-phase gas/oil-flow behavior in vertical pipes was studied experimentally and theoretically. A total of 149 air/high-viscosity-oil and 21 air/water experiments were conducted in a vertical pipe with an inner diameter (ID) of 50.8 mm. Six different oil viscosities—586, 401, 287, 213, 162, and 127 mPa·s—were considered. The superficial-liquid and -gas velocities were varied from 0.05 to 0.7 m/s and from 0.5 to 5 m/s, respectively. Flow pattern, pressure gradient, and average liquid holdup were measured and analyzed in this study. The experimental results were used to evaluate different flow-pattern maps, mechanistic models, and correlations for two-phase flow. Significant discrepancies between experimental and predicted results for pressure gradient were observed.

APA, Harvard, Vancouver, ISO, and other styles

50

Liu, Jinjin, Liu Kai, Tong Zhao, and Chuanxin Bai. "The Liquid Maldistribution Analysis of the Trickle Bed Reactor with the CFD Method." Mathematical Problems in Engineering 2020 (August 5, 2020): 1–10. http://dx.doi.org/10.1155/2020/7575392.

Full text

Abstract:

The liquid phase maldistribution factor has been investigated in trickle bed reactor, and the results are compared with the previous measurement data from literature by using the Electrical Resistance Tomography. The simulation results are in agreement with the experimental results to some degree. The flow rates and particle sizes have been simulated with the method of multiphase flow. There are two different particles with average diameters of 3.4 mm and 5.3 mm. The flow rate has been studied ranging from 100 ml/min to 1100 ml/min. It has been found that the changes of the particles and liquid flow rates have a significant impact on the distribution of the liquid volume fraction. The internal liquid holdup is more serious, and the wall-flow phenomenon is more obvious in a bigger flow rate. The prediction of the liquid volume fraction distribution is a key research technique. Regression predictions have also been researched on the section near outlet, which can predict the internal flow state of the trickle bed under the condition of high temperature and high pressure. The average liquid volume fraction is linear with flow rates. The maldistribution factor is the index correlation with the flow rates. The results and main conclusions can be used to predict the distributions and get the properties in a trickle bed reactor.

APA, Harvard, Vancouver, ISO, and other styles

Journal articles on the topic 'Liquid Holdup in Vertical Multiphase Flow'

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles