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Modeling of Flow of Nano-filled Viscoelastic Fluids and its Application in Rheometry
, M.Sc. Thesis Sharif University of Technology ; Ramazani Saadatabadi, Ahmad (Supervisor)
Abstract
Despite of passing many years from invention of Computational Fluid Dynamics (CFD), simulation of the fluid-solid interfaces and free surfaces are still completely challenging and progressive problems. In addition knowing and understanding nanotechnology huge applications,modeling of nano-fluids have been became a priority for researchers. Adding importance of Non-Newtonian fluids (especially polymeric solutions) to this two subjects, triangle topics of this research becomes vivid. In this research tried to consider and examine behavior of Newtonian,Generalized-Newtonian, Viscoelastic and nano-filled viscoelastic fluids in one and two phase mediums. we followed mesh free methods which are...
Experimental Study of Spray Pattern of Two Impinging Jets of Non-Newtonian Gel Fluid Containing Aluminum Nanoparticles
, M.Sc. Thesis Sharif University of Technology ; Kebriaee, Azadeh (Supervisor)
Abstract
In most of the studies conducted on the physics of the outflow from impinging jet injectors, Newtonian fluids have been used for their research and experiments. These studies have investigated the effect of factors such as geometrical parameters of the injector and physical properties of the fluid on different regimes resulting from the impact of the jet stream; Unfortunately, very few studies have been conducted on how to form spray and atomization in gel non-Newtonian fluids containing nanoparticles to investigate the above factors when using impinging jet injectors. Furthermore, although the addition of nanoparticles has advantages for better combustion, there are still problems in...
Analysis of non-newtonian fluids in microchannels with different wall materials
, Article ASME 2009 7th International Conference on Nanochannels, Microchannels, and Minichannels ; 2009 , Pages 697-703 ; 9780791843499 (ISBN) ; Behshad Shafii, M ; Safari Mohsenabad, S ; Sharif University of Technology
Abstract
The behavior of non-Newtonian fluids is considered as an important subject in micro scale and microfluidic flow researches. Because of the complexity and cost in the numerical works and the experimental set-ups in some instances, the analytical approach can be taken into account as a robust alternative tool to solve the non-Newtonian microfluidic flows in some special cases benefiting from a few simplified assumptions. In this work, we analyze the flow of two non-Newtonian fluids including the power-law and grade-fluid models in microchannels. For the grade-fluid, the stress tensors are defined considering the Rivlin-Ericksen tensor definitions. To avoid the complexities in the entrance...
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...
The effect of hematocrit and nanoparticles diameter on hemodynamic parameters and drug delivery in abdominal aortic aneurysm with consideration of blood pulsatile flow
, Article Computer Methods and Programs in Biomedicine ; Volume 195 , October , 2020 ; Nasiri Sadr, A ; Kaffash, E ; Goudarzi, S ; Golab, E ; Karimipour, A ; Sharif University of Technology
Elsevier Ireland Ltd
2020
Abstract
Background and Objective: The present article has simulated to investigate the efficient hemodynamic parameters, the drug persistence, and drug distribution on an abdominal aortic aneurysm. Methods: Blood as a non-Newtonian fluid enters the artery acting as a real pulse waveform; its behavior is dependent on hematocrit and strain rate. In this simulation of computational fluid dynamic, magnetic nanoparticles of iron oxide which were in advance coated with the drug, are injected into the artery during a cardiac cycle. A two-phase model was applied to investigate the distribution of these carriers. Results: The results are presented for different hematocrits and the nanoparticle diameter. It...
Introducing a rheology model for non-newtonian drilling fluids
, Article Geofluids ; Volume 2021 , 2021 ; 14688115 (ISSN) ; Sedaghat, A ; Misbah, B ; Sabati, M ; Vaidyan, K ; Mostafaeipour, A ; Dehshiri, S. S. H ; Almutairi, K ; Issakhov, A ; Sharif University of Technology
Hindawi Limited
2021
Abstract
An API standard drilling fluid was investigated from laminar to turbulent flow conditions using an in-house-built viscometer at speeds from 200 to 1600 RPM. A power-based method was applied to obtain the apparent viscosity and the shear stress of the water-based drilling mud (WBM) in the annulus of the viscometer. Then, a MATLAB optimization program was developed to obtain model parameters for five rheology models integrated in a generalized Herschel-Bulkley-Extended (HBE) model and two widely used 4-parameter models in drilling industry. It is found that the Bingham, Cross, and HBE rheology models have precisely matched the WBM measurements in the viscometer. A generalized Reynolds number...
Electrokinetic mixing and displacement of charged droplets in hydrogels
, Article Transport in Porous Media ; Vol. 104, Issue. 3 , Jun , 2014 , pp. 469-499 ; ISSN: 01693913 ; Sharif University of Technology
Abstract
Mixing in droplets is an essential task in a variety of microfluidic systems. Inspired by electrokinetic mixing, electric field-induced hydrodynamic flow inside a charged droplet embedded in an unbounded polyelectrolyte hydrogel is investigated theoretically. In this study, the polyelectrolyte hydrogel is modeled as a soft, and electrically charged porous solid saturated with a salted Newtonian fluid, and the droplet is considered an incompressible Newtonian fluid. The droplet-hydrogel interface is modeled as a surface, which is located at the plane of shear, with the electrostatic potential ζ. The fluid inside the droplet attains a finite velocity owing to hydrodynamic coupling with the...
Electroosmotic flow of power-law fluids with temperature dependent properties
, Article Journal of Non-Newtonian Fluid Mechanics ; Volume 185-186 , 2012 , Pages 49-57 ; 03770257 (ISSN) ; Saidi, M. H ; Sadeghi, A ; Sharif University of Technology
Elsevier
2012
Abstract
The influence of variable fluid properties on mixed electroosmotic and pressure driven flow of non-Newtonian fluids is investigated in this paper. The non-linear coupled energy and momentum equations are solved by means of an iterative numerical approach. The results reveal that the temperature dependent effects only become significant at very high values of the Debye-Hückel parameter in case of combined electroosmotic and pressure driven flow and could safely be neglected in other cases. It is observed that the physical properties variation lead to a higher mean velocity in case of pressure assisted flow and a lower mean velocity in case of pressure opposed flow. Furthermore, the...
A numerical study of the effects of blood rheology and vessel deformability on the hemodynamics of carotid bifurcation
, Article Scientia Iranica ; Volume 19, Issue 1 , February , 2012 , Pages 119-125 ; 10263098 (ISSN) ; Firoozabadi, B ; Saidi, M. S ; Sharif University of Technology
2012
Abstract
Hemodynamic factors, such as Wall Shear Stress (WSS), play a substantial role in arterial diseases. In the larger arteries, such as the carotid artery, interaction between the vessel wall and blood flow affects the distribution of hemodynamic factors. In the present study, both rigid-wall and deformable-wall models are developed in a 3D numerical simulation to assess the effectiveness of arterial rigidity on worsening hemodynamics, especially WSS. Two different rheological models (Newtonian and CarreauYasuda) have been employed to evaluate the influence of blood, non-Newtonian properties, as well. The importance of vessel wall deformability was compared with the rheological model of blood....
Mass transport analysis of non-Newtonian fluids under combined electroosmotically and pressure driven flow in rectangular microreactors
, Article Colloids and Surfaces A: Physicochemical and Engineering Aspects ; Volume 508 , 2016 , Pages 345-359 ; 09277757 (ISSN) ; Saidi, M. H ; Sharif University of Technology
Elsevier
Abstract
Hydrodynamically fully developed flow of power-law fluids under combined action of electroosmotic and pressure gradient forces in rectangular microreactors is analyzed considering heterogeneous catalytic reactions. The Poisson-Boltzmann, Cauchy momentum, and concentration equations are considered in two dimensions and after being dimensionless are numerically solved applying a finite difference algorithm. Variation of axial concentration gradient, and axial and horizontal mass diffusions are taken into account as well. To accomplish a more general analysis, the velocity distribution is obtained by solving continuity and Cauchy momentum equations and is not considered as an average axial...
Numerical simulation for efficient mixing of newtonian and non-Newtonian fluids in an electro-osmotic micro-mixer
, Article Chemical Engineering and Processing: Process Intensification ; Volume 107 , 2016 , Pages 11-20 ; 02552701 (ISSN) ; Mirzakhanloo, M ; Dabirzadeh, M. R ; Sharif University of Technology
Elsevier
2016
Abstract
The present study, deals with a new mixing technique using a two-phase electrode array, which is charged with alternating current (AC) signals, located in specific parts of the geometry. This significantly contributes to a chaotic mixing mechanism using a low amplitude AC voltage within a micro-channel. Study analysis demonstrates that the optimization of the effective parameters such as geometrical features, voltage amplitude, fluid inlet velocity, AC frequency and phase lag for a defined fluid can lead to an optimum and highly efficient mixer by considerably increasing disturbances in a primary highly ordered laminar flow. Three different geometries of micro mixer are studied; one-ring...
Pressure drop reduction of power-law fluids in hydrophobic microgrooved channels
, Article Physics of Fluids ; Volume 31, Issue 7 , 2019 ; 10706631 (ISSN) ; Moosavi, A ; Sharif University of Technology
American Institute of Physics Inc
2019
Abstract
Using hydrophobic surfaces is one of the efficient methods to preserve energy in fluid transfer systems. However, the studies have been concentrated on Newtonian fluids despite the wide applications of non-Newtonian fluids in daily life and many industries such as the biological, foodstuff, chemical, petroleum, cosmetic, and lab on a chip fields. In this study, we consider power-law fluids as a typical example of non-Newtonian fluids and investigate the effect of hydrophobic microgrooves on the pressure drop in channels by utilizing the phase field method. We demonstrate that the optimum size of the rectangular microgrooves in which the maximum pressure drop reduction (PDR) happens for both...
Experimental investigation of the bubble motion and its ascension in a quiescent viscous liquid
, Article Experimental Thermal and Fluid Science ; Volume 103 , 2019 , Pages 274-285 ; 08941777 (ISSN) ; Shahsavari, M ; Afshin, H ; Firoozabadi, B ; Sharif University of Technology
Elsevier Inc
2019
Abstract
In the present research, the rising behavior of air bubble in a viscous liquid is investigated experimentally. Aqueous solutions of glycerol and CMC were used as the Newtonian and shear-thinning non-Newtonian viscous liquids, respectively. The bubble is formed via injection of air by a syringe pump and rises in the quiescent viscous liquid. The process was captured using a high-speed camera (1000 fps) and was post processed to obtain the bubble characteristics such as the center of mass and aspect ratio. The experimental results were verified using the existing literatures and the non-dimensional numbers were reduced to two (Velocity number and Flow number) by lumping the parameters. In...
Electrowetting of power-law fluids in microgrooved channels
, Article Physics of Fluids ; Volume 32, Issue 7 , July , 2020 ; Moosavi, A ; Sharif University of Technology
American Institute of Physics Inc
2020
Abstract
Studying the dynamic behavior of droplets is of great importance in the electrowetting phenomena. However, despite the widespread use of non-Newtonian fluids in industry and daily life including medicine, food, petroleum, environmental biomass, and lab on a chip, most studies have focused on Newtonian fluids. In this study, a power-law fluid is considered as a typical example of non-Newtonian fluids and its dynamic behavior is investigated within a microchannel, and the results are compared with those of the Newtonian fluids. Both the grooved and non-grooved substrates are considered. For this purpose, the governing equations for the two phase fluid flow are solved using the finite element...
Computational simulation of non-Newtonian blood flow in carotid bifurcation for investigation the various rheological blood models
, Article ASME 2007 International Mechanical Engineering Congress and Exposition, IMECE 2007, 11 November 2007 through 15 November 2007 ; Volume 2 , 2007 , Pages 263-270 ; 0791842967 (ISBN) ; Firoozabadi, B ; Goodarzvand Chegini, A ; ASME ; Sharif University of Technology
American Society of Mechanical Engineers (ASME)
2007
Abstract
One of the leading causes for death after heart diseases and cancer in all over the world is still stroke. Most strokes happen because an artery carrying blood from the heart to the brain is clogged. Most of the time, as with heart attacks, the problem is atherosclerosis, hardening of the arteries, calcified build up of fatty deposits on the vessel wall. The primary troublemaker is the carotid artery, one on each side of the neck, the main thoroughfare for blood to the brain. In this study, the fluid dynamic simulations were done in the carotid bifurcation artery for studying the formation of atherosclerosis, and shear thinning behavior of blood as well as Newtonian comportment was studied....
Effect of non-Newtonian flow due to thermally-dependent properties over an inclined surface in the presence of chemical reaction, Brownian motion and thermophoresis
, Article Alexandria Engineering Journal ; Volume 60, Issue 5 , 2021 , Pages 4931-4945 ; 11100168 (ISSN) ; Ahmad, A ; Ali, K ; Bashir, H ; Iqbal, M. F ; Sharif University of Technology
Elsevier B.V
2021
Abstract
The aim of present study is to investigate the convective heat and mass transfer in steady MHD boundary layer flow of an electrically conducting micropolar fluid over an inclined surface. Partial differential equations resulting from the mathematical modeling of the phenomenon are reduce to nonlinear ODEs, and a finite difference based scheme has been adopted to iteratively find the numerical solution by employing the successive over-relaxation (SOR) method. A self-developed computer code has been used in the MATLAB environment. Influence of chemical reaction, Brownian motion, thermophoresis, and viscous dissipation on the relevant features of the flow are discussed and analyzed through...
Effect of non-Newtonian flow due to thermally-dependent properties over an inclined surface in the presence of chemical reaction, Brownian motion and thermophoresis
, Article Alexandria Engineering Journal ; Volume 60, Issue 5 , 2021 , Pages 4931-4945 ; 11100168 (ISSN) ; Ahmad, A ; Ali, K ; Bashir, H ; Iqbal, M. F ; Sharif University of Technology
Elsevier B.V
2021
Abstract
The aim of present study is to investigate the convective heat and mass transfer in steady MHD boundary layer flow of an electrically conducting micropolar fluid over an inclined surface. Partial differential equations resulting from the mathematical modeling of the phenomenon are reduce to nonlinear ODEs, and a finite difference based scheme has been adopted to iteratively find the numerical solution by employing the successive over-relaxation (SOR) method. A self-developed computer code has been used in the MATLAB environment. Influence of chemical reaction, Brownian motion, thermophoresis, and viscous dissipation on the relevant features of the flow are discussed and analyzed through...
Shear-thinning droplet formation inside a microfluidic T-junction under an electric field
, Article Acta Mechanica ; Volume 232, Issue 7 , 2021 , Pages 2535-2554 ; 00015970 (ISSN) ; Honarmand, M ; Dizani, M ; Moosavi, A ; Kazemzadeh Hannani, S ; Sharif University of Technology
Springer
2021
Abstract
Researchers usually simplify their simulations by considering the Newtonian fluid assumption in microfluidic devices. However, it is essential to study the behavior of real non-Newtonian fluids in such systems. Moreover, using the external electric or magnetic fields in these systems can be very beneficial for manipulating the droplet size. This study considers the simulation of the process of non-Newtonian droplets’ formation under the influence of an external electric field. The novelty of this study is the use of a shear-thinning fluid as the droplet phase in this process, which has been less studied despite its numerous applications. The effects of an external electric field on this...
Modelling of power-law fluid flow through porous media using smoothed particle hydrodynamics
, Article Transport in Porous Media ; Volume 74, Issue 3 , 2008 , Pages 331-346 ; 01693913 (ISSN) ; Manzari, M. T ; Sharif University of Technology
2008
Abstract
The flow of non-Newtonian fluids through two-dimensional porous media is analyzed at the pore scale using the smoothed particle hydrodynamics (SPH) method. A fully explicit projection method is used to simulate incompressible flow. This study focuses on a shear-thinning power-law model (n < 1), though the method is sufficiently general to include other stress-shear rate relationships. The capabilities of the proposed method are demonstrated by analyzing a Poiseuille problem at low Reynolds numbers. Two test cases are also solved to evaluate validity of Darcy's law for power-law fluids and to investigate the effect of anisotropy at the pore scale. Results show that the proposed algorithm can...
Experimental investigation of rheological and morphological properties of water in crude oil emulsions stabilized by a lipophilic surfactant
, Article Journal of Dispersion Science and Technology ; Volume 34, Issue 3 , Feb , 2013 , Pages 356-368 ; 01932691 (ISSN) ; Ramazani, S. A. A ; Taghikhani, V ; Ghotbi, C ; Sharif University of Technology
2013
Abstract
Rheological behavior of two crude oils and their surfactant-stabilized emulsions with initial droplet sizes ranging from 0.5 to 75 μm were investigated at various temperatures under steady and dynamic shear testing conditions. In order to evaluate the morphology and Stability of emulsions, microscopic analysis was carried out over three months and average diameter and size distribution of dispersed droplets were determined. The water content and surfactant concentration ranged from 10 to 60% vol/vol and 0.1 to 10% wt/vol, respectively. The results indicated that the rheological properties and the physical structure and stability of emulsions were significantly influenced by the water content...