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Characterization of three-phase flow in porous media using the ensemble Kalman filter
, Article Scientia Iranica ; Volume 24, Issue 3 , 2017 , Pages 1281-1301 ; 10263098 (ISSN) ; Pishvaie, M. R ; Bozorgmehry Boozarjomehry, R ; Sharif University of Technology
Sharif University of Technology
2017
Abstract
In this study, the ensemble Kalman filter is used to characterize threephase flow in porous media through simultaneous estimation of three-phase relative permeabilities and capillary pressures from production data. Power-law models of relative permeability and capillary pressure curves are used and the associated unknown parameters are estimated by assimilating the measured historical data. The estimation procedure is demonstrated on a twin numerical setup with two different scenarios, in which a synthetic 2D reservoir under three-phase flow is considered. In the first scenario, all the endpoints are assumed to be known and only the shape factors are estimated during the assimilation...
Splitting dynamics of ferrofluid droplets inside a microfluidic T-junction using a pulse-width modulated magnetic field in micro-magnetofluidics
, Article Soft Matter ; Volume 17, Issue 5 , 2021 , Pages 1317-1329 ; 1744683X (ISSN) ; Dizani, M ; Honarmand, M ; Shafii, M. B ; Sharif University of Technology
Royal Society of Chemistry
2021
Abstract
Micro-magnetofluidics offers a promising tool for better control over the ferrofluid droplet manipulation which has been vastly utilized in biomedical applications in recent years. In this study, the ferrofluid droplet splitting under an asymmetric Pulse-Width-Modulated (PWM) magnetic field in a T-junction is numerically investigated using a finite volume method and VOF two-phase model. By utilizing the PWM magnetic field, two novel regimes of ferrofluid droplet splitting named as Flowing through the Same Branch (FSB) and Double Splitting (DS) have been observed for the first time. In the FSB regime, the daughter droplets move out of the same microchannel outlet, and in the DS regime, the...
Mechanistic Studies of Improved Oil Recovery under Forced Gravity Drainage GAGD Process
, Ph.D. Dissertation Sharif University of Technology ; Kharrat, Riyaz (Supervisor) ; Ghotbi, Cyrus (Supervisor) ; Pooladi Darvish, Mehran (Co-Advisor)
Abstract
Gas-oil displacement, when stabilized by gravity forces leads to high displacement efficiency, as manifested in high recovery factor associated with gas-cap drive and gravity drainage. The main objective of this research is improved understanding of drainage behavior and changes in flow properties when the importance of viscous, gravity and capillary forces varies. The influence of interplaying between controlling forces on relative permeabilities is also studied. Another objective of this work is to study effect of wettability on recovery under forced gravity drainage. To study drainage behavior under various dominant driving/resistive forces, a number of forced gravity drainage experiments...
Numerical Study and Optimization of Effective Parameters in Freeze Desalination
, M.Sc. Thesis Sharif University of Technology ; Afshin, Hossein (Supervisor)
Abstract
Freeze desalination as a water refining method has attracted a lot of attention due to its potential in lowering process energy consumption compared to other methods. This method is based on the fact that the dissolved salt is drained from the saline water during its freezing. The current study conducts a parametric study on freezing saline water in a cylindrical container to investigate the impact of geometric and functional factors affecting the desalination quality. This has been done by examining the aforesaid factors in the form of dimensionless parameters such as thermal Grashof number, solutal Grashof number, and Jacob number. In addition, in order to improve the desalination, a novel...
Mixed pressure and AC electroosmotically driven flow with asymmetric wall zeta potential and hydrophobic surfaces
, Article ASME 2013 Heat Transfer Summer Conf. Collocated with the ASME 2013 7th Int. Conf. on Energy Sustainability and the ASME 2013 11th Int. Conf. on Fuel Cell Science, Engineering and Technology, HT 2013 ; Volume 1 , 2013 ; 9780791855478 (ISBN) ; Sharif University of Technology
2013
Abstract
The present study examines Alternating Current (AC) electroosmotic flows in a parallel plate microchannel subject to constant wall temperature. Numerical method consists of a central finite difference scheme for spatial terms and a forward difference scheme for the temporal term. Asymmetric boundary conditions are assumed for Poison-Boltzmann equation for determining the electric double layer (EDL) potential distribution. The potential distribution is then used to evaluate the velocity distribution. The velocity distribution is obtained by applying slip boundary conditions on the walls which accounts for probable hydrophobicity of surfaces. After determining the velocity distribution...
Axisymmetric problem of energetically consistent interacting annular and penny-shaped cracks in piezoelectric materials
, Article Journal of Applied Mechanics, Transactions ASME ; Volume 78, Issue 2 , 2011 ; 00218936 (ISSN) ; Moeini Ardakani, S. S ; Eskandari, M ; Sharif University of Technology
Abstract
The axisymmetric problem of a concentric set of energetically consistent annular and penny-shaped cracks in an infinite piezoelectric body subjected to uniform far-field electromechanical loading is addressed. With the aid of a robust innovated technique, the pertinent four-part mixed boundary value problem (MBVP) is reduced to a decoupled Fredholm integral equation of the second kind. The results of two limiting cases of a single penny-shaped crack and a single annular crack are recovered. The contour plots of dimensionless intensity factors (IFs) at each crack front provide the stress and electric displacement intensity factors (SIFs and EDIFs, respectively) for all combination of crack...
Characterization of viscous fingering during displacements of low tension natural surfactant in fractured multi-layered heavy oil systems
, Article Chemical Engineering Research and Design ; Volume 96 , 2015 , Pages 23-34 ; 02638762 (ISSN) ; Shokrollahi, A ; Ghazanfari, M. H ; Rashtchian, D ; Sharif University of Technology
Institution of Chemical Engineers
2015
Abstract
Characterization of viscous fingering in low tension displacements especially for heavy oil surfactant pair in heterogeneous systems is neither straight forward nor well understood. In this work layered porous models containing fractures with different geometrical properties were used and the finger behavior during displacement of LTNS, as a new EOR agent, in heavy oil was quantified. Dynamic propagation of the fingers independent to the type of heterogeneity is well correlated with the dimensionless displacement time in a linearly form. And also, the rate of finger growth is nearly independent to the type of medium heterogeneity. When injection is scheduled through high permeable region in...
Analytical solution of chamber effective length in the axial engine
, Article ASME International Mechanical Engineering Congress and Exposition, Proceedings (IMECE), 12 November 2010 through 18 November 2010, Vancouver, BC ; Volume 7, Issue PARTS A AND B , 2010 , Pages 1095-1102 ; 9780791844441 (ISBN) ; Mozafari, A. A ; Saidi, M. H ; Ghafourian, A ; Sharif University of Technology
2010
Abstract
this research chamber effective length, which is the minimum chamber length required for complete combustion, for a dilute monopropellant spray, constant area, one dimensional and fixed volume engine is analytically predicted. A new evaporation rate in the form of dk +1 relation, instead of d 2 law, is introduced. In case of controlling the vaporization by radiative heat transfer, k is equal to zero, and when molecular processes control the vaporization, k will be equal to unity and in some cases the vaporization data need the value of k greater than one to fit properly to related equation. Development of this approach can be used in design of combustion chambers with optimum length and with...
Boundary drag force acting on an impenetrable nano-particle
, Article ASME 2010 10th Biennial Conference on Engineering Systems Design and Analysis, ESDA2010, 12 July 2010 through 14 July 2010, Istanbul ; Volume 3 , 2010 , Pages 469-473 ; 9780791849170 (ISBN) ; Kebriai, M. H ; Meigounpoury, M. R ; Sharif University of Technology
2010
Abstract
Flow over nano spheres is a fundamental problem encountered in many engineering technical problems and the motion of nano-particles is important in many technical areas, for example nano-organizms motion in aqueous media, super hydrophobic spray for coating materials, nano-capsules for detecting cancer, and additive nano-particles in oil and fuel for automotive engines. In this paper computations are performed to determine the steady flow forces acting on the stationary nano-tube for Reynolds numbers in the range of 0.1
Relationship between wetting properties and macroscale hydrodynamics during forced gravity drainage and secondary waterflood
, Article Petroleum Science and Technology ; Volume 28, Issue 8 , 2010 , Pages 804-815 ; 10916466 (ISSN) ; Kharrat, R ; Ghotbi, C ; Alipour Tabrizy, V ; Sharif University of Technology
Abstract
In order to relate the wetting properties at the pore scale to the macroscale prevailing forces, a series of experiments was performed in vertical porous media under forced gas invasion at various wettability conditions with partially spreading oil. To describe the dynamics of oil recovery in a three-phase flow condition, the downward gas flood experiments were continued by water injection from the bottom. Experimental results obtained in situations where the magnitudes of viscous, capillary, and gravity forces are comparable. We study the transition from flow configurations where the interface is stable with respect to viscous instability to flow configurations where viscous fingering...
Comparison of the membrane morphology based on the phase diagram using PVP as an organic additive and TiO2 as an inorganic additive
, Article Polymer (United Kingdom) ; Volume 97 , 2016 , Pages 559-568 ; 00323861 (ISSN) ; Safekordi, A ; Tavakolmoghadam, M ; Rekabdar, F ; Hemmati, M ; Sharif University of Technology
Elsevier Ltd
Abstract
The morphology of symmetric and asymmetric membranes obtained by precipitation can be rationalized by thermodynamic and kinetic parameters. Such parameters which the former relates to thermodynamic effect and the latter controls the time of separation of the cast solution film immersing in the non-solvent bath from the glass plate were calculated as dimensionless parameters for further analysis. Phase diagram was used to consider the role of thermodynamic. The kinetic properties of the membranes could be investigated by the rate of mass transfer between solvent and non-solvent. By adding additives to the polymer solution the desire for becoming two phase and also viscosity of the solution...
Bubble dynamics in rotating flow under an accelerating field
, Article Physics of Fluids ; Volume 30, Issue 8 , 2018 ; 10706631 (ISSN) ; Javadi, K ; Taeibi Rahni, M ; Sharif University of Technology
American Institute of Physics Inc
2018
Abstract
Three-dimensional bubble dynamics in rotating flow under an accelerating field such as a centrifugal one is studied in this work. We employ the lattice Boltzmann method in two phase flows to simulate bubble dynamics for different Bond and Morton numbers of 0.1, 1, 10, and 100 and 0.001, 0.01, 0.1, 1, 10, and 100, respectively. Another dimensionless number named as dimensionless force, F∗, which is the ratio of buoyancy force to centripetal force is defined to explain the dynamics of the bubbles. In this work, we consider 5×10-7≤F∗≤5. The results show that bubbles in rotating flows have different kinds of motions such as spinning, rotating, and translating. Based on the ratios of the forces...
Mass transfer coefficients of extracting Mo (VI) and W (VI) in a stirred tank by solvent extraction using mixture of Cyanex272 and D2EHPA
, Article Separation Science and Technology (Philadelphia) ; 2019 ; 01496395 (ISSN) ; Torab Mostaedi, M ; Outokesh, M ; Asadollahzadeh, M ; Sharif University of Technology
Taylor and Francis Inc
2019
Abstract
In this study, the mass transfer evaluation of an agitated liquid-liquid system for the extraction of molybdenum and tungsten from aqueous sulfate solution was investigated. It was found from batch experiments for separation of molybdenum from tungsten that the initial aqueous pH, Cyanex272 and D2EHPA concentration, contact time, dispersed phase volume fraction and impeller speed were optimized at 1.3, 0.07 M, 0.29 M, 15 min, 0.09 and 280 rpm, respectively. The results indicate that a suitable composition for stripping is 1.5 M NH4OH and 0.6 M NH4F. Furthermore, a modified correlation based on dimensionless numbers was derived for the prediction of continuous phase mass transfer in the...
Mass transfer coefficients of extracting Mo (VI) and W (VI) in a stirred tank by solvent extraction using mixture of Cyanex272 and D2EHPA
, Article Separation Science and Technology (Philadelphia) ; Volume 55, Issue 17 , 2020 , Pages 3140-3150 ; Torab Mostaedi, M ; Outokesh, M ; Asadollahzadeh, M ; Sharif University of Technology
Bellwether Publishing, Ltd
2020
Abstract
In this study, the mass transfer evaluation of an agitated liquid-liquid system for the extraction of molybdenum and tungsten from aqueous sulfate solution was investigated. It was found from batch experiments for separation of molybdenum from tungsten that the initial aqueous pH, Cyanex272 and D2EHPA concentration, contact time, dispersed phase volume fraction and impeller speed were optimized at 1.3, 0.07 M, 0.29 M, 15 min, 0.09 and 280 rpm, respectively. The results indicate that a suitable composition for stripping is 1.5 M NH4OH and 0.6 M NH4F. Furthermore, a modified correlation based on dimensionless numbers was derived for the prediction of continuous phase mass transfer in the...
Frequency characteristics of a viscoelastic graphene nanoplatelet–reinforced composite circular microplate
, Article JVC/Journal of Vibration and Control ; Volume 27, Issue 1-2 , 2021 , Pages 101-118 ; 10775463 (ISSN) ; Habibi, M ; NoormohammadiArani, O ; Shavalipour, A ; Moayedi, H ; Safarpour, H ; Sharif University of Technology
SAGE Publications Inc
2021
Abstract
This is the first research on the frequency analysis of a graphene nanoplatelet composite circular microplate in the framework of a numerical-based generalized differential quadrature method. Stresses and strains are obtained using the higher order shear deformation theory. The microstructure is surrounded by a viscoelastic foundation. Rule of the mixture is used to obtain varying mass density and Poisson’s ratio, whereas the module of elasticity is computed by a modified Halpin–Tsai model. Governing equations and boundary conditions of the graphene nanoplatelet composite circular microplate are obtained by implementing Hamilton’s principle. The results show that outer to inner radius ratio...
Damage assessment of RC arch structures using fractal analysis of crack patterns
, Article Nondestructive Characterization and Monitoring of Advanced Materials, Aerospace, Civil Infrastructure, and Transportation XV 2021, 22 March 2021 through 26 March 2021 ; Volume 11592 , 2021 ; 0277786X (ISSN); 9781510640139 (ISBN) ; Khaloo, A ; Sharif University of Technology
SPIE
2021
Abstract
Surface crack patterns can easily show the behavior of concrete elements and structures. However, visual damage inspection performed by experts is a subjective approach and is prone to inaccuracies. The quantification makes this process objective and more reliable. In that regards, the maximum crack width is used as a practical measurement. It has been shown that the crack width is not a good indicator of damage due to its inherent uncertainties; In fact, it might bounce back after unloading. As such, a dimensionless parameter so-called Fractal Dimension has been introduced as a robust index that can quantify the complexity of crack distribution efficiently. The present study aims to...
A novel force-based approach for designing armor blocks of high-crested breakwaters
, Article Scientia Iranica ; Vol. 21, issue. 3 , 2014 , pp. 534-547 ; ISSN: 10263098 ; Sarfaraz, M ; Sharif University of Technology
Abstract
Rubble-mound breakwaters are common marine structures that provide a safe area for human coastal activities. The stability of these structures against sea-waves requires their seaward slope to be protected by an armor layer consisting of natural rock or concrete units. To provide a safe breakwater, it is reasonable to establish a relation between the exerted wave loads and the stability of the armor units. However, up to now, the empirical design equations, derived from model tests, relate wave parameters to armor weight, and keeps the effect of wave loads in a black box. In this paper, a new approach, based on numerically-derived wave loads on the armor, is presented to evaluate the...
Sea-level rise impact on fresh groundwater lenses in two-layer small islands
, Article Hydrological Processes ; Vol. 28, issue. 24 , 2014 , p. 5938-5953 ; Mahmoodzadeh, D ; Ataie-Ashtiani, B ; Werner, A. D ; Simmons, C. T ; Sharif University of Technology
Abstract
The fresh groundwater lenses (FGLs) of small islands can be highly vulnerable to climate change impacts, including sea-level rise (SLR). Many real cases of atoll or sandy islands involve two-layer hydrogeological conceptualizations. In this paper, the influential factors that affect FGLs in two-layer small islands subject to SLR are investigated. An analytical solution describing FGLs in circular islands, composed of two geological layers, is developed for the simplified case of steady-state and sharp-interface conditions. An application of the developed model is demonstrated to estimate the FGL thickness of some real-world islands by comparison with existing FGL thickness data. Furthermore,...
Pressure and temperature functionality of paraffin-carbon dioxide interfacial tension using genetic programming and dimension analysis (GPDA) method
, Article Journal of Natural Gas Science and Engineering ; Volume 20 , September , 2014 , Pages 407-413 ; ISSN: 18755100 ; Jahromi, I. R ; Zolghadr, A ; Ayatollahi, S ; Sharif University of Technology
Abstract
A precise semi-empirical correlation for the calculation of interfacial tension (IFT) between the carbon dioxide and paraffin group to be used in an enhanced oil recovery process and the chemical industry is introduced. Genetic programming and dimension analysis (GPDA) are combined to create a correlation for the calculation of the equilibrium interfacial tension of the carbon dioxide and paraffin group, based on the explicit functionality of the pressure and temperature. The parameters of the correlation consist of critical temperature, critical pressure, density of paraffin at normal temperature, and diffusion coefficients. The pool of experimental data for developing the correlation...
Mixed-convection flow of nanofluids and regular fluids in vertical porous media with viscous heating
, Article Industrial and Engineering Chemistry Research ; Volume 50, Issue 15 , 2011 , Pages 9403-9414 ; 08885885 (ISSN) ; Golmakani, A ; Dehkordi, A. M ; Sharif University of Technology
2011
Abstract
In this article, the problem of combined forced and natural convection in a vertical porous channel for both regular fluids and nanofluids has been solved by perturbation and numerical methods, taking into account the influences of viscous heating and inertial force. In this regard, various types of viscous dissipation models, including the Darcy model, the power of drag force model, and the clear fluid compatible model, were considered to account for viscous heating. In addition, the mass flux of nanoparticles was also considered in terms of Brownian and thermophoresis mechanisms. The velocity and temperature distributions of both the regular fluid and nanofluid and the Nusselt number...