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two-phase-flow
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Parametric study of droplet formation and characteristics within microfluidic devices - A case study
, Article International Journal of Applied Mechanics ; Volume 12, Issue 7 , 2020 ; Shamloo, A ; Kazemzadeh Hannani, S ; Sharif University of Technology
World Scientific
2020
Abstract
Droplet-based microfluidics technologies hold great attention in a wide range of applications, including chemical analysis, drug screening, and food industries. This work aimed to describe the effects of different physical properties of the two immiscible phases on droplet formation in a flow-focusing microfluidic device and determining proper flow rates to form a droplet within the desired size range. A numerical model was developed to solve the governing equations of two-phase flow and the results were validated with previous experimental results. The results demonstrate different types of droplet formation regimes from dripping to jetting and different production rates of droplets as a...
A numerical solution of 2D Buckley-Leverett equation via gradient reproducing kernel particle method
, Article CMES - Computer Modeling in Engineering and Sciences ; Volume 32, Issue 1 , 2008 , Pages 17-33 ; 15261492 (ISSN) ; Hashemian, A ; Sharif University of Technology
2008
Abstract
Gradient reproducing kernel particle method (GRKPM) is a meshless technique which incorporates the first gradients of the function into the reproducing equation of RKPM. Therefore, in two-dimensional space GRKPM introduces three types of shape functions rather than one. The robustness of GRKPM's shape functions is established by reconstruction of a third-order polynomial. To enforce the essential boundary conditions (EBCs), GRKPM's shape functions are modified by transformation technique. By utilizing the modified shape functions, the weak form of the nonlinear evolutionary Buckley-Leverett (BL) equation is discretized in space, rendering a system of nonlinear ordinary differential equations...
Experimental investigation of factors affecting miscible two-phase flow in fractured and non-fractured micromodels
, Article Proceedings of the 6th International Conference on Nanochannels, Microchannels, and Minichannels, ICNMM2008, 23 June 2008 through 25 June 2008, Darmstadt ; Issue PART B , 2008 , Pages 1027-1034 ; 0791848345 (ISBN); 9780791848340 (ISBN) ; Kharrat, R ; Ghazanfari, M. H ; ASME ; Sharif University of Technology
2008
Abstract
Micromodel is small-scale artificial model of porous medium which is known as a novel approach for simulating flow and transport in porous media. For better understanding the effect of fracture geometrical properties on oil recovery efficiency, a series of first contact miscible solvent injection process were conducted on horizontal glass micromodels at several fixed flow rate conditions. The micromodels were initially saturated with the heavy crude oil. The produced oil as a function of injected volume of solvents was measured using image analysis of the provided pictures. The concentration calibration curves of solvents in heavy crude oil were used for evaluating the solvents...
Simulation of wetting tendency of fluids with high density ratios using RK Lattice Boltzmann method
, Article 16th Asian Regional Conference on Soil Mechanics and Geotechnical Engineering, ARC 2019, 14 October 2019 through 18 October 2019 ; 2020 ; Pak, A ; Sadeghi, H ; Sharif University of Technology
Asian Regional Conference on Soil Mechanics and Geotechnical Engineering
2020
Abstract
Several lattice Boltzmann models for multi-phase flow have been developed, but few of them are capable of modeling fluid flows with high density ratio in the order of 1000. Therefore, an advanced chromodynamics, Rothmann-Keller (RK) type model is employed in current study, which can handle liquid-gas density ratio in the order of 1000 and viscosity ratio in the order of 100. Other distinctive characteristics of the proposed model are high stability, and capability of setting parameters such as surface tension independently. In spite of these benefits, the original RK model fails to model wetting tendency of the fluids. As a result, it is impossible to correctly simulate two-fluid phase flow...
Flow regime mapping for a two-phase system of aqueous alginate and water droplets in T-junction geometry
, Article Physics of Fluids ; Volume 33, Issue 7 , 2021 ; 10706631 (ISSN) ; Saadatmand, M ; Sharif University of Technology
American Institute of Physics Inc
2021
Abstract
Microfluidic systems are an interesting topic for investigation due to their wide-spreading applications. Nowadays, polymeric solutions are used mainly for the generation of microparticles in biomedical engineering, food, and pharmaceutical industries. Droplet-based microfluidic devices have proposed an extensive interest in many applications such as chemical/biological/nanomaterial preparation to understand deeply the droplet size and formation in microchannels. However, numerous experimental and numerical studies have been done for oil-water combination, polymeric solutions behavior in the presence of oil has not been investigated widely. Therefore, it is important to understand the...
Numerical simulation of cold and hot water injection into naturally fractured porous media using the extended–FEM and an equivalent continuum model
, Article International Journal for Numerical and Analytical Methods in Geomechanics ; 2021 ; 03639061 (ISSN) ; Pirmoradi, P ; Khoei, A. R ; Sharif University of Technology
John Wiley and Sons Ltd
2021
Abstract
In this paper, a computational technique is presented for the isothermal and non-isothermal water injection into naturally fractured oil reservoirs. A remarkable number of naturally fractured reservoirs contain relatively heavy oils that could not be extracted economically; hence, the thermal recovery methods are extensively used for such reservoirs. In this study, the effectiveness of hot water injection over cold (isothermal) water injection in oil production is quantified. The influence of long and short fractures and their alignments on oil recovery are discussed. To this end, a 2D model for two-phase fluid flow and heat transfer is presented. The medium is assumed to be partially...
Experimental and CFD simulation of slurry flow in the annular flow path using two-fluid model
, Article Journal of Petroleum Science and Engineering ; Volume 198 , 2021 ; 09204105 (ISSN) ; Jamshidi, S ; Sharif University of Technology
Elsevier B.V
2021
Abstract
The current study is allocated to experimental evaluation of the multiphase flow of fine solid particles (FSPs) as well as comprehensive numerical study in an annular space under static, laminar, and turbulent flow conditions with consideration of the inner pipe eccentricity and rotation. The experimental investigation was carried out using an annular pipe flow loop. The numerical modeling and simulation of the multiphase flow in the annular space have been performed using the Euler-Euler approach. The unsteady-state multiphase model based on the kinetic theory of granular flow (KTGF) is developed to investigate the particulate flow characteristics in the annular space. Moreover, Standard...
Simulation of two-phase flow by injecting water and surfactant into porous media containing oil and investigation of trapped oil areas
, Article Journal of Petroleum Exploration and Production ; Volume 11, Issue 3 , 2021 , Pages 1353-1362 ; 21900558 (ISSN) ; Jamshidi, S ; Kamalipoor, M ; Sharif University of Technology
Springer Science and Business Media B.V
2021
Abstract
Nowadays, as the oil reservoirs reaching their half-life, using enhanced oil recovery methods is more necessary and more common. Simulations are the synthetic process of real systems. In this study, simulation of water and surfactant injection into a porous media containing oil (two-phase) was performed using the computational fluid dynamics method on the image of a real micro-model. Also, the selected anionic surfactant is sodium dodecyl sulfate, which is more effective in sand reservoirs. The effect of using surfactant depends on its concentration. This dependence on concentration in using injection compounds is referred to as critical micelle concentration (CMC). In this study, an...
An integrated approach for predicting asphaltenes precipitation and deposition along wellbores
, Article Journal of Petroleum Science and Engineering ; Volume 203 , 2021 ; 09204105 (ISSN) ; Husein, M. M ; Ghotbi, C ; Taghikhani, V ; Dabir, B ; Sharif University of Technology
Elsevier B.V
2021
Abstract
Deposition of asphaltenes upon precipitation is a main flow assurance concern, which propelled the development of various experimental and modeling techniques to accurately predict its occurrence. This work develops an integrated approach combining thermodynamic and deposition modules with a multiphase flow simulator to simultaneously model asphaltenes precipitation and deposition in wellbores. The Peng-Robinson equation of state and the modified Miller-Flory-Huggins theory are used to calculate the thermodynamic properties of the oil and asphaltenes precipitation, respectively. The deposition module is based on conservation laws for asphaltenes transport and is linked to the flow simulator...
Pore-doublet computational fluid dynamic simulation of the effects of dynamic contact angle and interfacial tension alterations on the displacement mechanisms of oil by low salinity water
, Article International Journal of Multiphase Flow ; Volume 143 , 2021 ; 03019322 (ISSN) ; Fatemi, M ; Sharif University of Technology
Elsevier Ltd
2021
Abstract
Using our recently developed model, for the first time in the literature, the effect of fluid/fluid and rock/fluid interactions on the performance of Low Salinity Waterflooding (LSWF, as an Enhanced Oil Recovery process) at pore-doublet scale is investigated. The model is incorporated into OpenFOAM and both the Navier-Stokes equation for oil/water two-phase flow and the advection-diffusion equation for ion transport (at both fluid/fluid and rock/fluid interface) are solved via direct numerical simulation (DNS). The model is validated against imbibition and drainage pore-doublet experiments reported in the literature, and then applied to investigate the sole effect of wettability alteration...
Direct numerical simulation of the effects of fluid/fluid and fluid/rock interactions on the oil displacement by low salinity and high salinity water: Pore-scale occupancy and displacement mechanisms
, Article Journal of Petroleum Science and Engineering ; Volume 196 , 2021 ; 09204105 (ISSN) ; Fatemi, M ; Mousavi, M ; Sharif University of Technology
Elsevier B.V
2021
Abstract
Laboratory experiments have shown that performance of waterflooding in oil reservoirs could be significantly increased by lowering the ionic strength and/or manipulation of its composition, which is generally known as low salinity waterflooding (LSWF). The involved mechanisms in additional oil production can be generally categorized in two categories, fluid/fluid and fluid/rock interactions. The distribution of the phases and the involved displacement mechanisms would be strongly affected by the inter-relations between capillary and viscous forces. Although there have been recent advances in the simulation of the LSWF at core scale and beyond and some models are included in commercial...
Pore-doublet computational fluid dynamic simulation of the effects of dynamic contact angle and interfacial tension alterations on the displacement mechanisms of oil by low salinity water
, Article International Journal of Multiphase Flow ; Volume 143 , 2021 ; 03019322 (ISSN) ; Fatemi, M ; Sharif University of Technology
Elsevier Ltd
2021
Abstract
Using our recently developed model, for the first time in the literature, the effect of fluid/fluid and rock/fluid interactions on the performance of Low Salinity Waterflooding (LSWF, as an Enhanced Oil Recovery process) at pore-doublet scale is investigated. The model is incorporated into OpenFOAM and both the Navier-Stokes equation for oil/water two-phase flow and the advection-diffusion equation for ion transport (at both fluid/fluid and rock/fluid interface) are solved via direct numerical simulation (DNS). The model is validated against imbibition and drainage pore-doublet experiments reported in the literature, and then applied to investigate the sole effect of wettability alteration...
Direct numerical simulation of the effects of fluid/fluid and fluid/rock interactions on the oil displacement by low salinity and high salinity water: pore-scale occupancy and displacement mechanisms
, Article Journal of Petroleum Science and Engineering ; Volume 196 , 2021 ; 09204105 (ISSN) ; Fatemi, M ; Mousavi, M ; Sharif University of Technology
Elsevier B.V
2021
Abstract
Laboratory experiments have shown that performance of waterflooding in oil reservoirs could be significantly increased by lowering the ionic strength and/or manipulation of its composition, which is generally known as low salinity waterflooding (LSWF). The involved mechanisms in additional oil production can be generally categorized in two categories, fluid/fluid and fluid/rock interactions. The distribution of the phases and the involved displacement mechanisms would be strongly affected by the inter-relations between capillary and viscous forces. Although there have been recent advances in the simulation of the LSWF at core scale and beyond and some models are included in commercial...
Flow Pattern Prediction in iPWR SMR with Natural Circulation by Coupling of RELAP and ANSYS CFX Code
, M.Sc. Thesis Sharif University of Technology ; Ghafari, Mohsen (Supervisor)
Abstract
Selection of appropriate thermohydraulic tool for analyzing nuclear reactors is a trade of between accuracy and calculation run-time. Nuclear reactors analyses perform on two levels including system and sub-channel. In this regard or the system codes' one-dimensional approach is selected or the CFD codes for considering the three-dimensional and non-equilibrium phenomenon are employed. In this research a T-H tool for prediction of light-water cooled reactors core is developed. Although this code requires lower CPU and run-time in comparison with CFD codes, in contrast with system codes can report non-equilibrium and three-dimensional phenomenon. This code has a modular implementation based...
Mechanistic Investigation of Enhanced Oil Recovery by Engineered Water Using Computational Fluid Dynamics at Pore Scale
, Ph.D. Dissertation Sharif University of Technology ; Ayatollahi, Shahaboddin (Supervisor) ; Mahani, Hassan (Supervisor)
Abstract
Despite the proven advantage of the engineered water flooding technique, a coherent and mechanistic understanding of the fundamental phenomena occurring at pore scale is lacking. Most of the available simulation models have a phenomenological approach and have limited predictive capability. One of the key questions is how to justify and relate large (Darcy) scale observations to effects and phenomena that essentially occur at much smaller scales (i.e. pore and molecular level). Furthermore, two-phase flow dynamics and the effect of complex interplay between wettability, capillary number, and ions dispersion in a heterogeneous porous medium on the trapping and mobilization of oil at pore...
Three dimensional heat transfer modeling of gas-solid flow in a pipe under various inclination angles
, Article Powder Technology ; Vol. 262, Issue. 1 , 2014 , pp. 223-232 ; ISSN: 0032-5910 ; Saffar Avval, M ; Mansoori, Z ; Amirkhosravi, M ; Sharif University of Technology
Abstract
The turbulent heat transfer in gas-solid flows through an inclined pipe under various inclination angles is studied with constant wall heat flux. The hydrodynamic k- τ and kθ- τθ thermal two phase model is used in a lagrangian/Eulerian four way approach. The numerical results agreed reasonably with available experimental data in vertical and horizontal pipe flows. The effects of inclination angles on the flow patterns are reported. The pressure drop and Nusselt number are enhanced significantly as the inclination increases up to a certain angle. The mass loading ratio has influence on the optimal inclination angle. With increasing loading ratio, the optimal inclination angle of maximum...
Hydro-mechanical modeling of cohesive crack propagation in multiphase porous media using the extended finite element method
, Article International Journal for Numerical and Analytical Methods in Geomechanics ; Volume 37, Issue 10 , 2013 , Pages 1247-1279 ; 03639061 (ISSN) ; Khoei, A. R ; Sharif University of Technology
2013
Abstract
SUMMARY: In this paper, a numerical model is developed for the fully coupled hydro-mechanical analysis of deformable, progressively fracturing porous media interacting with the flow of two immiscible, compressible wetting and non-wetting pore fluids, in which the coupling between various processes is taken into account. The governing equations involving the coupled solid skeleton deformation and two-phase fluid flow in partially saturated porous media including cohesive cracks are derived within the framework of the generalized Biot theory. The fluid flow within the crack is simulated using the Darcy law in which the permeability variation with porosity because of the cracking of the solid...
Two phase modal analysis of nonlinear sloshing in a rectangular container
, Article Ocean Engineering ; Volume 38, Issue 11-12 , August , 2011 , Pages 1277-1282 ; 00298018 (ISSN) ; Firouz Abadi, R. D ; Ghasemi, M ; Sharif University of Technology
2011
Abstract
Sloshing, or liquid free surface oscillation, in containers has many important applications in a variety of engineering fields. The modal method can be used to solve linear sloshing problems and is the most efficient reduced order method that has been used during the previous decade. In the present article, the modal method is used to solve a nonlinear sloshing problem. The method is based on a potential flow solution that implements a two-phase analysis on sloshing in a rectangular container. According to this method, the solution to the mass conservation equation, with a nonpenetration condition at the tank walls, results in velocity potential expansion; this is similar to the mode shapes...
Experimental investigation of air-water, two-phase flow regimes in vertical mini pipe
, Article Scientia Iranica ; Volume 18, Issue 4 B , August , 2011 , Pages 923-929 ; 10263098 (ISSN) ; Saidi, M. H ; Nouri Gheimasi, A ; Ghanbarzadeh, S ; Sharif University of Technology
2011
Abstract
In this study, the flow patterns of air-water, two-phase flows have been investigated experimentally in a vertical mini pipe. The flow regimes were observed by a high speed video recorder in pipes with diameters of 2,3 and 4 mm and length 27, 31 and 25 cm, respectively. The comprehensive visualization of air-water, two-phase flow in a vertical mini pipe has been performed to realize the physics of such a two-phase flow. Different flow patterns of air-water flow were observed simultaneously in the mini pipe at different values of air and water flow rates. Consequently, the flow pattern map was proposed for flow in the mini-pipe, in terms of superficial velocities of liquid and gas phases. The...
Three-dimensional simulation of turbulent flow in 3-sub channels of a VVER-1000 reactor
, Article Scientia Iranica ; Volume 17, Issue 2 B , 2010 , Pages 83-92 ; 10263098 (ISSN) ; Firoozabadi, B ; Sharif University of Technology
2010
Abstract
In this study, the fluid dynamics and convective heat transfer for turbulent flows through a 3-sub channel of a rod bundle, which is representative of those used in VVER-1000, are examined. The rod bundle is constructed from parallel rods in a hexagonal array. The rods are on constant pitch by spacer grids spaced axially along the rod bundle. The geometry details of the bundle and heat flux from the fuel rod are similar to that of the Iranian nuclear reactor under construction. A numerical study using Computational Fluid Dynamics (CFD) was carried out to estimate the flow field, pressure loss and heat transfer coefficients in spacer grids and rod bundles. Turbulence has been modeled using...