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two-phase-flow
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Reservoir flow simulation using combined vorticity-based gridding and multi-scale upscaling
, Article Society of Petroleum Engineers - SPE Asia Pacific Oil and Gas Conference and Exhibition 2007 ""Resources, Professionalism, Technology: Time to Deliver"", Jakarta, 30 October 2007 through 1 November 2007 ; Volume 2 , 2007 , Pages 927-946 ; 9781604238594 (ISBN) ; Ashjari, M. A ; Firoozabadi, B ; Sharif University of Technology
Society of Petroleum Engineers (SPE)
2007
Abstract
A novel technique for upscaling of detailed geological reservoir descriptions is presented. The technique aims at reducing both numerical dispersion and homogenization error, generated due to incorporating a coarse computational grid and assigning effective permeability to coarse grid blocks respectively. In particular we consider implicit-pressure explicit-saturation (IMPES) scheme where homogenization error impacts the accuracy of the coarse grid solution of the pressure equation. To reduce the homogenization error, we employ the new vorticity-based gridding that generates a non-uniform coarse grid with high resolution at high vorticity zones. In addition, to control numerical dispersion,...
A new multiscale modeling framework for investigating thermally-induced flow maldistribution in multi-stream plate-fin heat exchangers
, Article International Journal of Heat and Mass Transfer ; Volume 180 , 2021 ; 00179310 (ISSN) ; Saidi, M. H ; Hannani, S. K ; Sharif University of Technology
Elsevier Ltd
2021
Abstract
Multi-stream Plate-fin heat exchangers (MSPFHEs) are among the most efficient heat exchangers in energy-based industries. They should be carefully designed to have maximum effectiveness and to avoid wasting energy. Flow maldistribution could significantly degrade the performance of heat exchangers. This study presents a novel modeling framework to capture the thermally-induced maldistribution in two-phase MSPFHEs. The developed model is used to show how thermally-induced flow maldistribution affects the performance of the heat exchanger, and some possible modifications are investigated to reduce its consequences. Our case study results show that thermally-induced maldistribution decreases...
Numerical Simulation of Two-Phase Annular Flow in Horizontal Tubes
, M.Sc. Thesis Sharif University of Technology ; Nouri Borujerdi, Ali (Supervisor)
Abstract
Two-phase flows are widely used in petrochemical industry, chemical processes, boilers, nuclear reactors, cooling systems and air conditioning equipment. Since the problem of earth’s ozone layer and global warming, the analysis of flow characteristics in evaporators are necessary to improve performance of refrigerating systems and saving the environment. Most of the researchers have been studied the evaporation of two phase flow refrigerant through experimental studies and numerical analysis has less attention in the literature. In this Thesis, a mathematical model based on the two-phase separated flow model is developed to simulate the evaporation of pure refrigerant under constant heat...
Mass Transfer Modeling while Formation of Liquid Jet to another Liquid
, M.Sc. Thesis Sharif University of Technology ; Bastani, Darioush (Supervisor)
Abstract
Liquid-liquid extraction is one of most important processes in chemical industries. So determination of operating condition effects is very critical. In this thesis we modeled concentration profile in the jet via mathematical equations and compare with experimental data. The major problem in concentration profile and solving equations is lack of knowledge in velocity profile within the jet was formed. Therefore, different flow models such as piston flow model, parabolic flow model, vortex flow model and a cone flow model was used and terminal concentrations inside the jet compared with laboratory values. Results shows the most accurate model to predict the flow concentration along the...
Comparison of dual Porosity-Dual Permeability Models in 2D Two-Phase Immiscible Flows under Gravitational Effect
, M.Sc. Thesis Sharif University of Technology ; Taghizadeh Manzari, Mehrdad (Supervisor) ; Kazemzadeh Hannani, Siamak (Co-Advisor)
Abstract
Physics of the present work is 2D two-phase immiscible flow under gravitational effect through fractured porous media and the most practical formulas for transfer function in dual porosity-dual permeability models have been implemented for numerical simulation of naturally fractured reservoir. The models are: Kazemi et al. (1976), Gilman (1986), Sonier et al. (1988), Quandalle and Sabathier (1989), Lim and Aziz (1995), and Rangel-German and Kovscek (2006), which are compared using a benchmark problem and the effects of gravity, capillary, number of matrix block subdomains and dual continuum media model are studied. The benchmark problem was adopted from Gilman (1986) and involves water...
, M.Sc. Thesis Sharif University of Technology ; Borgheei, Mahmoud (Supervisor)
Abstract
Air entering in to the water supply systems and occurrence of two-phase flow makes several problems in design and operation of these systems by damaging the structures and making indefinite and complicated conditions. Existence of some singularities like contractions in pipelines makes the conditions more indefinite. So an experimental study is performed in order to investigate the two-phase flow hydraulic properties in a rectangular channel in presence of an area contraction. The contraction ratio is σ=0.44, whereby the test section is included two different rectangular channels from 60 × 100 mm to 40 × 67 mm. Four series of experiments are performed using four types of transitions with...
Modeling and Performance Investigation of Airlift Pump with Conical Upriser Pipe
, M.Sc. Thesis Sharif University of Technology ; Saeedi, Mohammad Hassan (Supervisor)
Abstract
Airlift pumps are widely used in numerous industries for different applications such as transmission of viscous fluids (heavy hydrocarbons of oil), pumping of corrosive liquids and so on. In general, parameters which affect the efficiency of an airlift pump can be classified into two major groups. The first group is the designing parameters such as the diameter of the upriser pipe or the submergence ratio. The second group is the operation parameters such as diameter of the bubble, inlet pressure of the gas and so on. One of the designing parameters which can have an effective influence on the performance of an airlift pump is the non-constant diameter of the upriser pipe, which can be...
Experimental Investigation of Mass Transfer by Droplet Using Image Processing
, M.Sc. Thesis Sharif University of Technology ; Firoozabadi, Bahar (Supervisor) ; Afshin, Hossein ($item.subfieldsMap.e)
Abstract
Wide and varied aspects of droplet motion due to its increasing application in various fields has attracted much attention. Analysis of mass transfer from the liquid drop into the other fluid, such as complex and intriguing problems in fluid mechanics, which is very important. Many experimental and numerical studies have been carried out in this case that the evelopment of laboratory equipment and software, are rapidly growing.
In this study, given the importance of this issue, experimental study on mass transfer in fluid systems solution droplet liquid - liquid extraction, have been considered. Different methods have been discussed to date. In the present study, using image processing...
In this study, given the importance of this issue, experimental study on mass transfer in fluid systems solution droplet liquid - liquid extraction, have been considered. Different methods have been discussed to date. In the present study, using image processing...
Modeling and Simulation of Two Phase Flow in Gas Condensate Wells
, M.Sc. Thesis Sharif University of Technology ; Taghikhani, Vahid (Supervisor) ; Ghazanfari, Mohammad Hossein (Supervisor)
Abstract
A numerical simulation of fluid flow in gas condensate wellbore, which annular flow is dominant, is performed. A three fluid model is used for annular two phase flow. The model is based on conservation equations of mass, momentum and energy for gas phase, dispersed phase (droplets) and the film. The friction between phases and with wellbore wall and also mass transfer between phases, which conservation equations rely on them, are considered. Computer programming of obtained system of equations is performed in Matlab. The Reimann method is used for solving our system of hyperbolic equations and simulation is performed for both steady and unsteady state. Transforming system of nonlinear...
Numerical Simulation of two Phase Flow Around Gas- Condensate Wells With Compositional Model
, M.Sc. Thesis Sharif University of Technology ; Taghizadeh Manzari, Mehrdad (Supervisor) ; Seif, Mohammad Saeid (Supervisor) ; Kazemzade Hannani, Siamak (Supervisor)
Abstract
If the reservoir temperature lies between the critical temperature and cricondentherm of the reservoir fluid, the reservoir is classified as a retrograde gas-condensate reservoir. When the pressure is decreased on these mixtures, instead of expanding or vaporizing as might be expected, they vaporize instead of condensing. If the reservoir pressure is above the upper dew-point pressure, the hydrocarbon system exists as a single phase in the reservoir (region 3). As the reservoir pressure declines isothermally during production from the initial pressure to the upper dew-point pressure, the attraction between the molecules of the light and heavy components move further apart. As this occurs,...
Flow Regime Recognition and Pressure Drop Simulation in Vertical Air-Water Flow By Means of Neural Networks and Fuzzy Logic
, M.Sc. Thesis Sharif University of Technology ; Saeedi, Mohammad Hassan (Supervisor)
Abstract
In order to safe design and optimize performance of industrial systems which work under two phase flow conditions, it’s often needed to categorize flow into different regimes. In present work the experiments of two phase flow were done in a large scale test facility with length of 6m and 5cm diameter. Four main flow regimes were observed in vertical air-water two phase flows at moderate superficial velocities of gas and water: Bubbly, Slug, Churn and Annular. Some image processing techniques were used to extract information from each picture. This information includes number of bubbles or objects, area, perimeter, height and width of objects (second phase). Also a texture feature extraction...
Comparison of interface capturing methods in two phase flow
, Article Iranian Journal of Science and Technology, Transaction B: Engineering ; Volume 29, Issue 6 , 2005 , Pages 539-548 ; 03601307 (ISSN) ; Jahanbakhsh, E ; Seif, M. S ; Sharif University of Technology
2005
Abstract
In two phase flow investigation, there is a need for robust methods capable of predicting interfaces, in addition to treating the traditional governing equations of fluid mechanics (Navier-Stokes Eqs.). Such methods in a finite volume approach can be classified into two typical categories called interface tracking and interface capturing methods. According to their abilities, interface capturing methods are of more interest in free surface modeling, especially when complex interface topologies such as wave breaking are included. These methods solve a scalar transport equation in order to find the distribution of two phases all over the computational domain. That is, all properties of the...
DNAPL flow and complex electrical resistivity evolution in saturated porous media: A coupled numerical simulation
, Article Journal of Contaminant Hydrology ; Volume 248 , 2022 ; 01697722 (ISSN) ; Deparis, J ; Leroy, P ; Ataie Ashtiani, B ; Davarzani, H ; Colombano, S ; Sharif University of Technology
Elsevier B.V
2022
Abstract
Induced Polarization (IP) is a non-intrusive geophysical method to monitor Dense Non-Aqueous Phase Liquid (DNAPL) contamination and remediation processes underground. In this study, an advanced numerical code simulating DNAPL flow and complex electrical resistivity is presented. The model was validated against existing IP results and image measurements that were carried out previously in a series of 2D tank experiment. Multiphase flow modeling in porous media is coupled with electrical current modeling to simulate the process of DNAPL migration and the associated IP response. This brings a broader view of the contamination in space and time compared to surface and borehole measurements,...
Visual technique for detection of gas-liquid two-phase flow regime in the airlift pump
, Article Journal of Petroleum Science and Engineering ; Volume 75, Issue 3-4 , January , 2011 , Pages 327-335 ; 09204105 (ISSN) ; Ghanbarzadeh, S ; Saidi, M. H ; Sharif University of Technology
Abstract
Simplicity of manufacturing and high reliability of airlift pumps have promoted these pumps to be used in different industries, such as petrochemical and oil industries, especially in oil recovery from dead wells. One of the main parameters affecting the performance of these pumps is two-phase flow regime in the main pipe of the pump. In this research, experimental data are utilized to investigate the influence of the flow regimes on the performance of an airlift pump. The data are obtained for air-water two-phase flow in a vertical pipe with a diameter of d = 50. mm and an aspect ratio of L/d = 120. In this study, the gas liquid upward two-phase flow regime in the upriser pipe is...
A heuristic insight on end-point calculation and a new phase interference parameter in two-phase relative permeability curves for horizontal fracture flow
, Article Transport in Porous Media ; Volume 119, Issue 3 , 2017 , Pages 499-519 ; 01693913 (ISSN) ; Shad, S ; Taghikhani, V ; Ayatollahi, S ; Sharif University of Technology
Abstract
Relative permeability curves of two-phase flow in a fracture have been a subject of study in recent years. The importance of these curves have been widely observed in multidisciplines, such as water subsurface resources, geothermal energy and underground hydrocarbon resources, especially fractured oil and gas reservoirs. Extensive experimental studies have been cited alongside the numerical studies in this area. However, simple analytical and practical solutions are still attractive. In the current study, wettability effects and phase interference explicitly were tried to be implemented in a simple analytical formula. The wettability effects are represented by residual saturations which...
Equilibrium and non-equilibrium gas–liquid two phase flow in long and short pipelines following a rupture
, Article AIChE Journal ; Volume 63, Issue 7 , 2017 , Pages 3214-3223 ; 00011541 (ISSN) ; Shafiei Ghazani, A ; Sharif University of Technology
John Wiley and Sons Inc
2017
Abstract
The two-phase flow following the blowdown of pipeline carrying flashing liquid is numerically investigated by using thermodynamic equilibrium and non-equilibrium models. Model equations are solved numerically by the finite volume method. The values of fluxes at cell boundaries are obtained by AUSM+-up. To obtain proper values for the coefficients of dissipation, both single phase liquid and two phase shock tube problems are investigated. The transient release from the pressurized pipeline is studied for two cases of long and short pipes. Comparison of the predictions against experimental data reveals non-equilibrium model performs a little better than equilibrium model in the prediction of...
Numerical investigation of two phase flow in micromodel porous media: effects of wettability, heterogeneity, and viscosity
, Article Canadian Journal of Chemical Engineering ; Volume 95, Issue 6 , 2017 , Pages 1213-1223 ; 00084034 (ISSN) ; Rokhforouz, M. R ; Ayatollahi, S ; Sharif University of Technology
Wiley-Liss Inc
2017
Abstract
The aim of the present work is to assess the effects of wettability, heterogeneity, and viscosity differences on water-oil displacement process in micromodel porous media through numerical modelling. The two-phase flow was simulated by Cahn-Hilliard phase field method (PFM) using a finite element package. The micromodel was initially saturated with oil (wetting phase) and oil was produced through invasion of the displacing phase into the matrix. The computed oil and water saturations were in good agreement with those obtained by the visual flooding experiment. Using the validated model, sensitivity analysis was performed to investigate the effects of different wettability states,...
Effect of operating conditions on the performance of a PEM fuel cell
, Article International Journal of Heat and Mass Transfer ; Volume 144 , 2019 ; 00179310 (ISSN) ; Sharif University of Technology
Elsevier Ltd
2019
Abstract
In this study, a two-phase flow model based on species transport, energy, and electrochemical equations was developed for polymer electrolyte membrane fuel cell (PEMFC). The influences of heat sources and sinks, and water transport inside the fuel cell were also taken into account. In this regard, the effect of the operating conditions including cell temperature and pressure, anode and cathode inlet humidity, and anode and cathode stoichiometric ratios on the fuel cell performance was investigated. The simulation results show that inlet humidity and stoichiometric ratio of the anode side, cell pressure and temperature, and distribution of the heat sources and sinks are crucial factors...
Theoretical comparative assessment of single- and two-phase models for natural convection heat transfer of Fe3O4/ethylene glycol nanofluid in the presence of electric field
, Article Journal of Thermal Analysis and Calorimetry ; 2020 ; Tavakoli, S ; Pishvaie, M. R ; Sharif University of Technology
Springer Netherlands
2020
Abstract
Natural convective heat transfer of Fe3O4/ethylene glycol nanofluids around the platinum wire as a heater in the absence and presence of the high electric field was investigated, numerically. The control volume finite element method was employed for the numerical simulation. Effects of the flow model, the volume fraction of nanoparticles, Rayleigh number, and the electric field intensity on the natural heat transfer coefficient (NHTC) of nanofluid were studied. Simulation results of single-phase and two-phase flow models showed that the two-phase model could better predict experimental data than the single-phase model due to take into account the velocity of each phase in the mixture. The...
Friction reduction in grafted carbon nanochannels by applying an electric field
, Article Computational Materials Science ; Volume 213 , 2022 ; 09270256 (ISSN) ; Moosavi, A ; Hannani, S. K ; Sharif University of Technology
Elsevier B.V
2022
Abstract
Water can be pumped in nanochannels by limiting it between the surfaces with different hydrophobicities and exerting a spinning electric field. The asymmetrical hydrophobicity combined with the spinning electric field and the fact that the water molecules have a dipole moment create a situation in which the angular momentum of water molecules is transformed into a linear momentum and the water is pumped into the nanochannel. The hydrophobicity of the surfaces can be manipulated by using nanostructures to reduce friction. In this study, two types of nanostructures have been used which are hierarchical nanostructures and polymer nanostructures made of Poly(N-isopropylacrylamide). The walls of...