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apparent-viscosity
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Feasibility Study of Capillary Blood Viscosity Estimation using MRI
, M.Sc. Thesis Sharif University of Technology ; Samadfam, Mohammad (Supervisor) ; Ashoor, Mansoor (Co-Advisor)
Abstract
Magnetic resonance imaging is one of non-invasive methods to measure the hemodynamic and morphologic parameters of tissues, especially brain tissues. Hemodynamic parameters monitoring in brain tissue is of significant importance in many majors such as detection of tumor occurrence, brain abnormalities, and track of treatment procedures. Blood is a suspension, comprised of plasma, red blood cells, white blood cells, platelet, etc. Plasma is a Newtonian fluid which is composed of proteins and has a constant viscosity in body temperature. Rheological properties of blood are highly dependent on mechanical and rheological properties of its cells and this dependence is multiplied in narrow vessels...
Viscosity estimation of semi-solid alloys by drop weight backward extrusion test under high speed deformation
, Article Semi-Solid Processing of Alloys and Composites 10 - Selected, peer reviewed papers from the 10th International Conference on Semi-Solid Processing of Alloy and Composites, S2P 2008, Aachen, 16 September 2008 through 18 September 2008 ; Volume 141-143 , 2008 , Pages 379-384 ; 10120394 (ISSN); 9771012039401 (ISBN) ; Aashuri, H ; Khosravani, A ; Foroughi, A ; Sharif University of Technology
Trans Tech Publications Ltd
2008
Abstract
A simple method for estimating the apparent viscosity of semi-solid alloys was investigated. A drop weight of 50Kg and backward extrusion equipments were used to test the deformation. Backward extrusion was employed in a closed die system due to the very little separation of liquid from solid phases compared with other methods at very high deformation rate. The half of the calculated impact velocity, 700mm/s was considered as an average velocity for deformation during the test, since the slop of the velocity changes against time is constant in the middle stage of the deformation. The initial height of the sample and the thickness of the residual compressed solid at the bottom of the cup were...
Investigation of Rheological Behavior of Polymer on EOR in Carbonate Reservoir
, Ph.D. Dissertation Sharif University of Technology ; Ramazani Saadat Abadi, Ahmad (Supervisor) ; Emadi, Mohammad Ali (Supervisor)
Abstract
The major objectives of this study are to analytically and experimentally investigate the rheological behavior of polymers in the fractured carbonate medium based on the polymer solution properties and operational conditions. The intrinsic and apparent viscosity of high molecular weight-partially hydrolyzed poly (acrylamide) which is mainly used in enhanced oil recovery (EOR) processes hasbeen investigated in reservoir conditions. Since, the EOR efficiency of hydrolyzed poly (acrylamide) is very sensitive to the temperature and salinity of petroleumreservoirs; investigations have been carried out at different possible reservoirtemperatures using high saline polymer solutions. The parameters...
Study of Rheology of Suspensions Using SPH Method and Immersed Boundary Method
, M.Sc. Thesis Sharif University of Technology ; Taghizadeh Manzari, Mehrdad (Supervisor)
Abstract
In this thesis, an Incompressible SPH (ISPH) method is used to simulate suspensions. A suspension is assumed to be a mixture of solid particles in a Newtonian fluid. First, renormalization tensors are applied to the discretized equations of SPH method. This leads to a higher accuracy in this method. It should be noted that the projection method is used for ISPH. After that, the Immersed Boundary Method (IBM) is used to model and simulate the presence of solid particles in fluid flow. Some modifications were necessary to use IBM with Lagrangian approach. Then, some benchmark problems are solved to validate the presented method. The main objective of the present thesis is simulation of...
Experimental Investigation of Improvement of Stability and Performance of Foam Using Nano-particles to Enhance Oil Recovery
, M.Sc. Thesis Sharif University of Technology ; Ghazanfari, Mohammad Hossein (Supervisor)
Abstract
Using foam for reducing undesirable effects of fingering and gravity segregation in enhanced oil recovery through gas injection has attracted a rapidly increasing interest in recent years. Lack of stability of foam often limits its application. However there is a lack of systematic study of effects of unmodified and in-situ modified silica nano-particle on foam stability and foam behavior in the presence and absence of oil and also polymer effects from the prospective of analysis of foam dynamic stability, size of foam bubbles, and foam flow behavior in Hele – Shaw cell. Main objectives of this study are mechanistic investigation of effects of polymer – surfactant systems and in-situ...
Investigation of Oil-Asphaltene Slurry Rheological Behavior
, Article Journal of Dispersion Science and Technology ; Vol. 35, issue. 8 , Aug , 2013 , p. 1155-1162 ; ISSN: 01932691 ; Taghikhani, V ; Pishvaie, M. R ; Masihi, M ; Panuganti, S. R ; Chapman, W. G ; Sharif University of Technology
Abstract
The presence of asphaltene means additional difficulties related to transport and processing due to the increased crude oil viscosity caused by the asphaltene. For a better knowledge of the flow properties of asphaltene containing crude oils, it is necessary to understand how asphaltene affects the rheological properties. The aim of this article is to provide information on such rheological properties of oil-asphaltene slurry systems. The results of rheological experiments show that the non-Newtonian flow curves can be approximated by the Bingham plastic model to determine the apparent viscosity and the yield stress as a function of asphaltene concentration and temperature. An explanation is...
Influence of monoethanolamine on thermal stability of starch in water based drilling fluid system
, Article Shiyou Kantan Yu Kaifa/Petroleum Exploration and Development ; Volume 45, Issue 1 , 2018 , Pages 157-160 ; 10000747 (ISSN) ; Sharif Nik, M. A ; Heidari, H ; Valizadeh, M ; Sharif University of Technology
Science Press
2018
Abstract
To improve the thermal stability of starch in water-based drilling fluid, monoethanolamine (MEA) was added, and the effect was investigated by laboratory experiment. The experimental results show that the addition of monoethanolamine (MEA) increases the apparent viscosity, plastic viscosity, dynamic shear force, and static shear force of the drilling fluid, and reduces the filtration rate of drilling fluid and thickness of mud cake apparently. By creating hydrogen bonds with starch polymer, the monoethanolamine can prevent hydrolysis of starch at high temperature. Starch, as a natural polymer, is able to improve the rheological properties and reduce filtration of drilling fluid, but it works...
Development of a saturation-based μ(I)-rheology for wet granular materials using discrete element method
, Article Scientia Iranica ; Volume 28, Issue 5 B , 2021 , Pages 2719-2732 ; 10263098 (ISSN) ; Taghizadeh Manzari, M ; Hajilouy Benisi, A ; Sharif University of Technology
Sharif University of Technology
2021
Abstract
The present study employs Discrete Element Method (DEM) to establish a rheological model that relates the apparent viscosity of a granular material to shear rate, normal stress, and water saturation. In addition, a theoretical model was developed to determine water distribution and water-induced forces between particles for different saturations. The resulting forces were embedded in a 3D shear cell as a numerical rheometer, and a wet specimen was sheared between two walls. A power law rheological model was then obtained as a function of inertia number and saturation. It was found that up to a critical saturation, the apparent viscosity increased with saturation that was higher than that of...
The preparation and rheological investigation of polymer and hydrogel modified drilling mud
, Article Petroleum Science and Technology ; Volume 30, Issue 10 , 2012 , Pages 1059-1068 ; 10916466 (ISSN) ; Ramazani, S. A. A ; Khosravi, N ; Sharif University of Technology
2012
Abstract
The authors carried out the study to prepare chitosan N-isopropylacrylamide hydrogel via heating and radiation processes. Properties investigation of prepared samples revealed that radiation prepared samples show higher yield and swelling ratios in comparison with the heating prepared ones. Effects of hydrogel addition to drilling mud on its important rheological properties such as apparent viscosity, plastic viscosity, and stress-strain behavior are measured. The rheological properties of hydrogel were compared with cellulosemethylcarboxyl and resins that are widely used in drilling fluid. The results demonstrate that whereas linear polymer effects on mud properties are more significant in...
A mechanistic study of emulsion flooding for mobility control in the presence of fatty acids: Effect of chain length
, Article Fuel ; Volume 276 , 2020 ; Suleymani, M ; Sharif University of Technology
Elsevier Ltd
2020
Abstract
Emulsion flooding is a promising method for enhanced oil recovery (EOR). The static and dynamic behavior of the emulsions is greatly influenced by the nature of the applied surfactant. In this work, the effect of fatty acids, as natural surface-active agents, and their chain length on the emulsion behavior was investigated in both bulk and porous media. A panel of the fatty acids with different chain lengths (6 < C < 18) was applied at constant concentration and pH. Upon the static stability tests, emulsion stability at the optimum value of chain length (C14) was increased by two orders of magnitude. Under the optimal condition, the hydrogen bonding between dissociated and undissociated...
Static and dynamic behavior of foam stabilized by modified nanoparticles: Theoretical and experimental aspects
, Article Chemical Engineering Research and Design ; Volume 158 , 2020 , Pages 114-128 ; Ashoori, S ; Ghotbi, C ; Moghadasi, J ; Kharrat, R ; Sharif University of Technology
Institution of Chemical Engineers
2020
Abstract
Gas flooding is a practical secondary scenario for enhanced oil recovery. Channeling and fingering of the injected gas are the major problems facing this technique. These challenges can be mitigated by the injection of gas as foam. However, foam stability influences the overall efficiency of the process, which could be improved by nanoparticles (NPs). This work provides a theoretical and experimental analysis of the NPs wettability effects on foam behavior, in both static and dynamic states. The treated calcite (CaCO3) NPs along with a cationic surfactant (HTAB) were used for this purpose. By comparison of theoretical and experimental data, it was shown that the foam stability in the...
Investigation of bubble formation and its detachment in shear-thinning liquids at low capillary and Bond numbers
, Article Theoretical and Computational Fluid Dynamics ; Volume 33, Issue 5 , 2019 , Pages 463-480 ; 09354964 (ISSN) ; Afshin, H ; Firoozabadi, B ; Sharif University of Technology
Springer New York LLC
2019
Abstract
In the present paper, the formation of an air bubble in a shear-thinning non-Newtonian fluid was investigated numerically. For modeling, an algebraic volume of fluid (VOF) solver of OpenFOAM ® was improved by applying a Laplacian filter and was evaluated using the experimental results from the literature. The enhanced solver could compute the surface tension force more accurately, and it was important especially at low capillary and Bond numbers due to the dominance of surface tension force relative to the other forces. The adiabatic bubble growth was simulated in an axisymmetric domain for Bo = 0.05 , 0.1 , 0.5 and Ca = 10 - 1, 10 - 2, 10 - 3, 10 - 4, and the bubble detachment time and...
Friction reduction of Al2O3, SiO2, and TiO2 nanoparticles added to non-Newtonian water based mud in a rotating medium
, Article Journal of Petroleum Science and Engineering ; Volume 217 , 2022 ; 09204105 (ISSN) ; Sedaghat, A ; Rashidi, M ; Sabati, M ; Vaidyan, K ; Ali, N ; Omar, M. A. A ; Hosseini Dehshiri, S. S ; Sharif University of Technology
Elsevier B.V
2022
Abstract
In drilling industry, energy consumption counts from 20 to 40 percent of total costs. Enhanced water-based mud (WBM) drilling fluids with nanoparticles can save energy in drilling processes. An in-house Taylor-Couette flow system (TCS) was developed at Australian University (AU) to study WBM enhanced by Al2O3, SiO2, and TiO2 nanoparticles. The TCS is really a practical tool to help well drillers with a rough idea of viscosity when nanoparticles are added. The TCS for sure cannot substitute advanced rheometry. The goal of the present experiment is to produce a rough estimate in field operation. Experimental results were examined with several rheology models in our previous publications. In...