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porous-media
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Fluid flow and heat transfer in microchannel with and without porous medium under constant heat flux
, Article Sadhana - Academy Proceedings in Engineering Sciences ; Volume 47, Issue 2 , 2022 ; 02562499 (ISSN) ; Sharif University of Technology
Springer
2022
Abstract
In this study, the heat transfer and fluid flow characteristics of a three-dimensional microchannel that is partially filled with a layer of porous medium at its bottom solid wall is investigated. The microchannel is consisted of a clear fluid flow region, solid walls and a porous layer that is attached to its solid bottom wall. A constant heat flux is applied to the bottom wall of the microchannel. Darcy-Brinkman-Forchheimer model is used to simulate the fluid flow inside the porous medium. The novelty of this work is to investigate thoroughly and precisely the effect of using of porous layer configuration in MCHSs on hydraulic and thermal performances. The effect of porous layer thickness,...
Scaling, multifractality, and long-range correlations in well log data of large-scale porous media
, Article Physica A: Statistical Mechanics and its Applications ; Vol. 390, issue. 11 , June , 2011 , p. 2096-2111 ; ISSN: 03784371 ; Jafari, G. R ; Sahimi, M ; Masihi, M ; Sharif University of Technology
Abstract
Three distinct methods, namely, the spectral density, the multifractal random walk approach, and the multifractal detrended fluctuation analysis are utilized to study the properties of four distinct types of well logs from three oil and gas fields, namely, the natural gamma ray emission, neutron porosity, bulk density, and the sonic transient time logs. Such well logs have never been analyzed by the methods that we utilize in the present study. The results indicate that the well logs exhibit multifractal characteristics, and the estimated Hurst exponents by the three methods are close to each other. Using multifractal detrended fluctuation analysis and the shuffled and surrogated data, we...
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...
Dynamic responses of intervertebral disc during static creep and dynamic cyclic loading: A parametric Poroelastic finite element analysis
, Article Biomedical Engineering - Applications, Basis and Communications ; Volume 25, Issue 1 , 2013 ; 10162372 (ISSN) ; Haghpanahi, M ; Parnianpour, M ; Wang, J. L ; Sharif University of Technology
2013
Abstract
Low back pain is a common reason for activity limitation in people younger than 45 years old, and was proved to be associated with heavy physical works, repetitive lifting, impact, stationary work postures and vibrations. The study of load transferring and the loading condition encountered in spinal column can be simulated by finite element models. The intervertebral disc is a structure composed of a porous material. Many physical models were developed to simulate this phenomenon. The confounding effects of poroelastic properties and loading conditions on disc mechanical responses are, nevertheless, not cleared yet. The objective of this study was to develop an axisymmetric poroelastic...
Experimental investigation of matrix wettability effects on water imbibition in fractured artificial porous media
, Article Journal of Petroleum Science and Engineering ; Volume 86-87 , 2012 , Pages 165-171 ; 09204105 (ISSN) ; Ayatollahi, S ; Rostami, B ; Sharif University of Technology
Abstract
Spontaneous water imbibition into the matrix blocks is known as the main mechanism for increased oil recovery from naturally fractured oil reservoirs. The rate of oil recovery and its ultimate value is mostly affected by wettability of the rocks and their pore structure. Oil viscosity also greatly influences the rate of oil recovery. A novel experimental model was utilized to study the imbibition mechanism under different wettability conditions. Matrix blocks made from different grain types and size distributions of glass beads were saturated with two different types of synthetic oil, to mimic the oil-saturated matrixes. The wetting characteristic of the models used in this study were...
Simulation of activity loss of fixed bed catalytic reactor of MTO conversion using percolation theory
, Article Chemical Engineering Science ; Volume 66, Issue 23 , December , 2011 , Pages 6199-6208 ; 00092509 (ISSN) ; Khorasheh, F ; Sharif University of Technology
2011
Abstract
In this investigation, a reactor model for prediction of the deactivation behavior of MTO's porous catalyst in a fixed bed reactor is developed. Effect of coking on molecular transport in the porous structure of SAPO-34 has been simulated using the percolation theory. Thermal effects of the reaction were considered in the model and the temperature profile of the gas stream in the reactor was predicted. The predicted loss in catalyst activity with time-on-stream was in very good agreement with the experimental data. The resulting coke deposition and gas temperature profiles along the length of reactor suggested a reaction front moving toward the outlet of the fixed bed reactor at the...
Scaling, multifractality, and long-range correlations in well log data of large-scale porous media
, Article Physica A: Statistical Mechanics and its Applications ; Volume 390, Issue 11 , 2011 , Pages 2096-2111 ; 03784371 (ISSN) ; Jafari, G. R ; Sahimi, M ; Masihi, M ; Sharif University of Technology
2011
Abstract
Three distinct methods, namely, the spectral density, the multifractal random walk approach, and the multifractal detrended fluctuation analysis are utilized to study the properties of four distinct types of well logs from three oil and gas fields, namely, the natural gamma ray emission, neutron porosity, bulk density, and the sonic transient time logs. Such well logs have never been analyzed by the methods that we utilize in the present study. The results indicate that the well logs exhibit multifractal characteristics, and the estimated Hurst exponents by the three methods are close to each other. Using multifractal detrended fluctuation analysis and the shuffled and surrogated data, we...
Numerical modeling of multiphase fluid flow in deforming porous media: A comparison between two- and three-phase models for seismic analysis of earth and rockfill dams
, Article Computers and Geotechnics ; Volume 38, Issue 2 , March , 2011 , Pages 142-166 ; 0266352X (ISSN) ; Mohammadnejad, T ; Sharif University of Technology
Abstract
In this paper, a fully coupled numerical model is presented for the finite element analysis of the deforming porous medium interacting with the flow of two immiscible compressible wetting and non-wetting pore fluids. The governing equations involving coupled fluid flow and deformation processes in unsaturated soils are derived within the framework of the generalized Biot theory. The displacements of the solid phase, the pressure of the wetting phase and the capillary pressure are taken as the primary unknowns of the present formulation. The other variables are incorporated into the model using the experimentally determined functions that define the relationship between the hydraulic...
Pore-scale simulation of fluid flow passing over a porously covered square cylinder located at the middle of a channel, using a hybrid MRT-LBM–FVM approach
, Article Theoretical and Computational Fluid Dynamics ; Volume 29, Issue 3 , 2015 , Pages 171-191 ; 09354964 (ISSN) ; Taeibi Rahni, M ; Jam, F ; Sharif University of Technology
Springer New York LLC
2015
Abstract
A comprehensive study was performed to analyze the unsteady laminar flow characteristics around a porously covered, a fully porous, and a solid squared section cylinder located in the middle of a plane channel. In order to simulate fluid flow inside porous media and porous–fluid interface accurately (minimizing modeling error), the porous region was analyzed in pore scale, using LBM. Additionally, to minimize the LBM-related compressibility error through the porous region, a multi-block multiple relaxation time lattice Boltzmann method (MRT-LBM) was used. Also, to decrease CPU time, a Navier–Stokes flow solver, based on finite volume method and SIMPLE algorithm, was coupled with MRT-LBM to...
Efficiency enhancement of optimized Latin hypercube sampling strategies: Application to Monte Carlo uncertainty analysis and meta-modeling
, Article Advances in Water Resources ; Volume 76 , 2015 , Pages 127-139 ; 03091708 (ISSN) ; Ataie Ashtiani, B ; Janssen, H ; Sharif University of Technology
Abstract
The majority of literature regarding optimized Latin hypercube sampling (OLHS) is devoted to increasing the efficiency of these sampling strategies through the development of new algorithms based on the combination of innovative space-filling criteria and specialized optimization schemes. However, little attention has been given to the impact of the initial design that is fed into the optimization algorithm, on the efficiency of OLHS strategies. Previous studies, as well as codes developed for OLHS, have relied on one of the following two approaches for the selection of the initial design in OLHS: (1) the use of random points in the hypercube intervals (random LHS), and (2) the use of...
Elitist continuous ant colony optimization algorithm for optimal management of coastal aquifers
, Article Water Resources Management ; Volume 25, Issue 1 , 2010 , Pages 165-190 ; 09204741 (ISSN) ; Ketabchi, H ; Sharif University of Technology
2010
Abstract
This paper presents an evolutionary based approach to achieve optimal management of a coastal aquifer to control saltwater intrusion. An improved Elitist Continuous Ant Colony Optimization (ECACO) algorithm is employed for optimal control variables setting of coastal aquifer management problem. The objectives of the optimal management are; maximizing the total water-pumping rate, while controlling the drawdown limits and protecting the wells from saltwater intrusion. Since present work is one of the first efforts towards the application of an ECACO algorithm, sharp interface solution for steady state problem is first exploited. The performance of the developed optimization model is evaluated...
A numerical analysis of thermal conductivity, thermal dispersion, and structural effects in the injection part of the resin transfer molding process
, Article Journal of Porous Media ; Volume 13, Issue 4 , 2010 , Pages 375-385 ; 1091028X (ISSN) ; Karimi, M ; Seyf, H. R ; Sharif University of Technology
2010
Abstract
Thermal conductivity, thermal dispersion, and structural effects in resin transfer molding (RTM) process are studied numerically. The injection part of the RTM process is modeled as a transport of resin flow through a fibrous porous medium in a long rectangular channel. The fluid flow is modeled using the Darcy-Brinkman-Forchheimer model and the heat transfer process using the energy equation based on local thermal equilibrium assumption. Both isotropic and anisotropic heat transfer in porous media are investigated. The governing equations are solved numerically for the isotropic heat transfer case and analytically for the anisotropic case. The numerical results are fitted to the available...
Comparing sloshing phenomena in a rectangular container with and without a porous medium using explicit nonlinear 2-D BEM-FDM
, Article Scientia Iranica ; Volume 17, Issue 2 B , 2010 , Pages 93-101 ; 10263098 (ISSN) ; Ghodsi Hassanabad, M ; Sharif University of Technology
2010
Abstract
The sloshing phenomena in a partially filled tank can affect its stability. Modifications of tank instability due to the movement of the tank carrier, are key design points for the stability of a carrier. Even though the sloshing phenomenon has already been investigated using the BEM-FDM technique, the research in this paper covers this phenomenon in a porous media, which is new in 2-D coordinates. For this purpose, a Laplace equation has been used for potential flow, and kinematic and dynamic boundary conditions have been applied to the free surface. Also, a formulation has been developed for a free surface in porous media. BEM has been used for solving the governing equation and FDM...
Green element solution of one-dimensional counter-current spontaneous imbibition in water wet porous media
, Article Journal of Petroleum Science and Engineering ; Volume 70, Issue 3-4 , 2010 , Pages 302-307 ; 09204105 (ISSN) ; Pishvaie, M. R ; Sharif University of Technology
Abstract
A Green Element numerical formulation is used to solve the time-dependent nonlinear one-dimensional counter-current spontaneous imbibition diffusion equation in which water enters a water wet rock spontaneously while oil escapes by flowing in the opposite direction. The Green Element Method (GEM) is an element by element approach of the boundary element method. In this new method, by generating large sparse global matrices and yet taking advantage of properties of Green's function, solution of more complicated physical problem is achievable while at the same time much less computational effort is needed rather than boundary element method (BEM). By discretizing both the boundary and problem...
Dynamic modeling and optimization of asphaltene deposition in reservoir rocks using genetic algorithm
, Article 72nd European Association of Geoscientists and Engineers Conference and Exhibition 2010: A New Spring for Geoscience. Incorporating SPE EUROPEC 2010 ; Volume 6 , 2010 , Pages 4291-4295 ; 9781617386671 (ISBN) ; Kharrat, R ; Hemmatfar, V ; Ghotbi, C ; Sharif University of Technology
Society of Petroleum Engineers
2010
Abstract
Asphaltene deposition is a problematic challenge for oil production. Changes in key parameters like pressure and fluid composition during natural depletion and different gas injection scenarios may result in asphaltene precipitation and deposition. In this work, a model is developed by application of mass balance equations, momentum equation, asphaltene deposition and permeability reduction models. An algorithm is developed to perform iterative procedure to solve the numerical equations that contains highly coupled variables. Indeed, an equation is introduced to calculate the saturation of the precipitated asphaltene phase. Model parameters were determined by genetic algorithm which is a...
Investigating the effect of hybrid silica nanoparticles-copolymer on increasing oil recovery in a three dimensional porous media
, Article Scientia Iranica ; Volume 24, Issue 6 , 2017 , Pages 3466-3475 ; 10263098 (ISSN) ; Ramazani, A. S. A ; Hekmatzadeh, M ; Sharif University of Technology
Abstract
In this work, hybrid of silica nanoparticles (NPs) with sulfonated copolymer has been prepared in order to improve the copolymer properties for Enhanced Oil Recovery (EOR). Some tests are done to find the effectiveness of injecting fluid on Recovery Factor (RF), such as Contact Angle (CA), interfacial tension (IFT), inherent viscosity, and eventually Micro-Model (MM) flooding. In CA test, wettability alteration from Oil-Wet (OW) to Water-Wet (WW) is reached by sedimentation and adsorption of NPs on the rock slice. In addition, IFT reduction is obtained by increasing the NaCl concentration. The viscosity change is investigated for the hybrid and copolymer under simulated high-temperature oil...
A sequential implicit discrete fracture model for three-dimensional coupled flow-geomechanics problems in naturally fractured porous media
, Article Journal of Petroleum Science and Engineering ; Volume 150 , 2017 , Pages 312-322 ; 09204105 (ISSN) ; Shamloo, A ; Dezfuli, A. D ; Sharif University of Technology
Abstract
A sequential implicit numerical method based on discrete-fracture model and the Galerkin Finite Element method, for time-dependent coupled fluid flow and geomechanics problems in fractured subsurface formations is presented. Discrete-fracture model has been used to explicitly represent the fracture network inside porous media. The Galerkin Finite Element method with adaptive unstructured gridding is implemented to numerically solve the spatially three-dimensional and time-dependent problem. The presented method is validated with previously obtained solutions. Two problems are numerically solved by applying the presented methodology in a three-dimensional fractured petroleum reservoir under...
Relative permeabilities hysteresis for oil/water, gas/water and gas/oil systems in mixed-wet rocks
, Article Journal of Petroleum Science and Engineering ; Volume 161 , February , 2018 , Pages 559-581 ; 09204105 (ISSN) ; Sohrabi, M ; Sharif University of Technology
Elsevier B.V
2018
Abstract
Accurate determination of relative permeability (kr) curves and their hysteresis is needed for reliable prediction of the performance of oil and gas reservoirs. A few options (e.g., Carlson, Killough and Jargon models) are available in commercial reservoir simulators to account for hysteresis in kr curves under two-phase flow. Two-phase kr curves are also needed for estimating kr hysteresis under three-phase flow during water-alternating-gas (WAG) injection. Although, most oil reservoirs are mixed-wet, the existing hysteresis predictive approaches have been developed based on water-wet conditions. Experimentally measured data are needed to assess the performance of these methodologies under...
A quantitative and qualitative comparison of coarse grid generation techniques for numerical simulation of flow in heterogeneous porous media
, Article SPE Reservoir Simulation Symposium 2009, The Woodlands, TX, 2 February 2009 through 4 February 2009 ; Volume 1 , 2009 , Pages 55-73 ; 9781605607771 (ISBN) ; Mahani, H ; Firoozabadi, B ; Landmark; HALLIBURTON ; Sharif University of Technology
2009
Abstract
Applying upscaling techniques is an undeniable demand in reservoir simulation, considering the difference between level of details in a geological model and level of details that can be handled by reservoir simulators. Upscaling reservoir model involves first constructing a coarse grid by employing gridding algorithms and then computing average properties for coarse grid blocks. Although various techniques have been proposed for each of these steps, one has to be aware of strengths and weaknesses of each technique before attempting to apply them. In this paper, we focus on different gridding methods and evaluate their performances. Three main grid generation techniques are considered:...
Analyzing transient heat and moisture transport surrounding a heat source in unsaturated porous media using the Green's function
, Article Geothermics ; Volume 81 , 2019 , Pages 224-234 ; 03756505 (ISSN) ; Ghasemi Fare, O ; Sharif University of Technology
Elsevier Ltd
2019
Abstract
Generally, in most areas, groundwater level is deep and heat sources (e.g., energy piles)are embedded in unsaturated soil media. Therefore, in order to accurately analyze the soil response close to heat sources, both heat and moisture transport in unsaturated soil domain should be considered. Thermal loading changes the moisture content in the porous media. In this study, the energy conservation and mass fluid continuity equations derived from hydrothermal analysis of a partially saturated soil medium are considered in cylindrical coordinate system. To make the analytical solution possible, partial differential equations (PDEs)are turned into ordinary differential equations (ODEs), through...