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newtonian-liquids
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On the yield stress of magnetorheological fluids
, Article Chemical Engineering Science ; Volume 256 , 2022 ; 00092509 (ISSN) ; Alaghehband, N ; Bavil, P. K ; Sharif University of Technology
Elsevier Ltd
2022
Abstract
Magnetorheological fluids (MRFs) are a category of functional materials that exhibit magneto-mechanical coupling. These materials exhibit a reversible and instantaneous change from a free-flowing Newtonian fluid to a semi-solid state upon application of a magnetic field. In contrast to ordinary fluids, MRFs can tolerate shear stresses up to a yield value in the presence of a magnetic field. The yield stress strongly depends on intensity of the applied magnetic field and volume fraction of magnetic particles. As the yield stress is the most important parameter of an MRF and must be considered in the design of MR devices, in this work, effects of magnetic field and volume fraction of particles...
Heat transfer of power-law fluids under electrowetting actuation in structured microchannels
, Article International Communications in Heat and Mass Transfer ; Volume 130 , 2022 ; 07351933 (ISSN) ; Merdasi, A ; Moosavi, A ; Sharif University of Technology
Elsevier Ltd
2022
Abstract
The dynamics and heat transfer performance of droplets play an important role in electrowetting systems. Contrary to the growing trend towards non-Newtonian fluids in electrotechnical systems, most researchers have focused on Newtonian fluids. In the current study, the interface is tracked by the phase-field method and afterwards, the numerical model is confirmed by comparing the results obtained from previous experimental and theoretical works. Several parameters such as power-law index and contact angle are analyzed. Furthermore, the dynamics and heat transfer of the droplets on chemically or topographically structured substrates in the presence of electrowetting are examined. It has been...
Homotopy perturbation method for unsteady motion of a single bubble in a highly viscous liquid
, Article Chemical Engineering Communications ; Volume 208, Issue 8 , 2021 , Pages 1143-1159 ; 00986445 (ISSN) ; Oshaghi, M. R ; Afshin, H ; Firoozabadi, B ; Sharif University of Technology
Taylor and Francis Ltd
2021
Abstract
In this study, the dynamics of the accelerated and steady-state motion of a single bubble in a quiescent highly viscous Newtonian liquid was investigated theoretically and experimentally. The presented mathematical model was based on Newton's second law of motion and a balance of buoyancy, drag, history, and added-mass forces. Due to the presence of non-linear terms in the equation of motion, homotopy perturbation method was used as a powerful analytical method to calculate the velocity analytically. To obtain accurate results in the experiments, a high-speed camera was used to record the bubble motion from the moment of detachment to the time at which the terminal velocity is reached....
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...
Controlled drug delivery using the magnetic nanoparticles in non-Newtonian blood vessels
, Article Alexandria Engineering Journal ; 2020 ; Bantan, R. A. R ; Aalizadeh, F ; Alimoradi, A ; Sharif University of Technology
Elsevier B.V
2020
Abstract
Fouling in blood flow is very common and may decrease the blood flow in human body and lead to critical health issues. Upon injury in a blood vessel, the body's defensive system triggers a process to create a blood clot called “Thrombus”, which prevents bleeding. Blood clots are formed by a combination of blood cells, platelets, and fibrins. In this study, we investigate a controlled drug delivery using the magnetic nanoparticles in blood vessels under the influence of magnetic fields. For this purpose the Maxwell and the Navier-Stokes equations for the system are solved. In contrary to the previous studies it is assumed that the blood is a non-Newtonian fluid. The number of particles has...
Non-Newtonian fluid flow dynamics in rotating annular media: Physics-based and data-driven modeling
, Article Journal of Petroleum Science and Engineering ; Volume 185 , 2020 ; Amooie, M. A ; Shams, R ; Hajirezaie, S ; Liu, Y ; Jamshidi, S ; Soltanian, M. R ; Sharif University of Technology
Elsevier B.V
2020
Abstract
A thorough understanding and accurate prediction of non-Newtonian fluid flow dynamics in rotating annular media are of paramount importance to numerous engineering applications. This is in particular relevant to oil and gas industry where this type of flow could occur during, e.g., drilling, well completion, and enhanced oil recovery scenarios. Here, mathematically we report on physical-based (numerical) and data-driven (intelligent) modeling of three-dimensional laminar flow of non-Newtonian fluids driven by axial pressure gradient in annular media that consist of a coaxially rotating inner cylinder. We focus on the dynamics of pressure loss ratio (PLR)—the ratio of total pressure loss 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...
Controlling the microscale separation of immiscible liquids using geometry: A computational fluid dynamics study
, Article Chemical Engineering Science ; Volume 220 , 2020 ; Mohammadi, A ; Sharif University of Technology
Elsevier Ltd
2020
Abstract
In this study, we numerically determined the performance of a microscale separator comprising a lateral and a main channel to separate a two-phase flow. It was aimed to conduct continuous phase through the lateral channel and dispersed phase through the main channel. The continuous and dispersed phases were modeled as incompressible Newtonian fluids with the corresponding interface tracked by the phase-field model. The dynamics, including pressure fluctuations in the separator, were further examined. It was mechanistically demonstrated how the geometry of the separator modulates the phase separation. Further examined were the influences of various geometrical parameters on the performance of...
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...
Computational inertial microfluidics: a review
, Article Lab on a Chip ; Volume 20, Issue 6 , 2020 , Pages 1023-1048 ; Mashhadian, A ; Ehsani, A ; Saha, S. C ; Krüger, T ; Ebrahimi Warkiani, M ; Sharif University of Technology
Royal Society of Chemistry
2020
Abstract
Since the discovery of inertial focusing in 1961, numerous theories have been put forward to explain the migration of particles in inertial flows, but a complete understanding is still lacking. Recently, computational approaches have been utilized to obtain better insights into the underlying physics. In particular, fundamental aspects of particle focusing inside straight and curved microchannels have been explored in detail to determine the dependence of focusing behavior on particle size, channel shape, and flow Reynolds number. In this review, we differentiate between the models developed for inertial particle motion on the basis of whether they are semi-analytical, Navier-Stokes-based,...
Homotopy perturbation method for unsteady motion of a single bubble in a highly viscous liquid
, Article Chemical Engineering Communications ; 2020 ; Oshaghi, M. R ; Afshin, H ; Firoozabadi, B ; Sharif University of Technology
Taylor and Francis Ltd
2020
Abstract
In this study, the dynamics of the accelerated and steady-state motion of a single bubble in a quiescent highly viscous Newtonian liquid was investigated theoretically and experimentally. The presented mathematical model was based on Newton's second law of motion and a balance of buoyancy, drag, history, and added-mass forces. Due to the presence of non-linear terms in the equation of motion, homotopy perturbation method was used as a powerful analytical method to calculate the velocity analytically. To obtain accurate results in the experiments, a high-speed camera was used to record the bubble motion from the moment of detachment to the time at which the terminal velocity is reached....
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...
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...
Unsteady natural convection in a differentially heated rectangular enclosure possessing sinusoidal corrugated side walls loaded with power law non-newtonian fluid
, Article Fluid Dynamics ; Volume 54, Issue 2 , 2019 , Pages 159-176 ; 00154628 (ISSN) ; Abdolahi Sadatlu, M. A ; Sojoudi, A ; Sharif University of Technology
Pleiades Publishing
2019
Abstract
This research is a numerical analysis exhaustively investigating two-dimensional (2D) transient convective heat transfer in a differentially heated rectangle, possessing sinusoidal corrugated side walls at constant temperatures. The quadrilateral space is filled with a power-law non-Newtonian fluid, plus the right and left walls are uniformly cooled and heated, respectively. The top and bottom walls are retained as adiabatic and the side walls are recast exploiting sinusoidal corrugated shape. The governing equations of the problem are solved using the finite volume method. The evaluation of fluid flow and heat transfer is conducted in such a manner that the power law index n varies from 0.6...
Experimental study of two-phase oil – Polymer flow in horizontal flow path
, Article Experimental Thermal and Fluid Science ; Volume 100 , 2019 , Pages 62-75 ; 08941777 (ISSN) ; Shad, S ; Sharif University of Technology
Elsevier Inc
2019
Abstract
Two-phase flow inside the oil and gas wells and flow path lines is a usual occurrence in petroleum and petrochemical studies. Due to its complexity, flow transfer parameters such as hold up and pressure drop and their dependency on the flow regime maps are not well understood yet. This study is aimed at analyzing holdup for oil- water system and evaluation of this parameter by means of Image processing under different available flow regime conditions. In addition, different oil-polymer systems have been studied to evaluate the impact of polymer concentration on transport criteria. The experimental setup used for this study is consisted of a 12 m long Plexiglas pipe with an inner diameter of...
Experimental study of two-phase oil – Polymer flow in horizontal flow path
, Article Experimental Thermal and Fluid Science ; Volume 100 , 2019 , Pages 62-75 ; 08941777 (ISSN) ; Shad, S ; Sharif University of Technology
Elsevier Inc
2019
Abstract
Two-phase flow inside the oil and gas wells and flow path lines is a usual occurrence in petroleum and petrochemical studies. Due to its complexity, flow transfer parameters such as hold up and pressure drop and their dependency on the flow regime maps are not well understood yet. This study is aimed at analyzing holdup for oil- water system and evaluation of this parameter by means of Image processing under different available flow regime conditions. In addition, different oil-polymer systems have been studied to evaluate the impact of polymer concentration on transport criteria. The experimental setup used for this study is consisted of a 12 m long Plexiglas pipe with an inner diameter of...
DPD simulation of non-Newtonian electroosmotic fluid flow in nanochannel
, Article Molecular Simulation ; Volume 44, Issue 17 , 2018 , Pages 1444-1453 ; 08927022 (ISSN) ; Zakeri, R ; Darbandi, M ; Sharif University of Technology
Taylor and Francis Ltd
2018
Abstract
We use the dissipative particle dynamics (DPD) method to simulate the non-Newtonian electroosmotic flow (EOF) through nanochannels. Contrary to a large amount of past computational efforts dedicated to the study of EOF profile, this work pays attention to the EOF of non-Newtonian fluids, which has been rarely touched in past publications. Practically, there are many MEMS/NEMS devices, in which the EOF behaviour should be treated assuming both non-continuum and non-Newtonian conditions. Therefore, our concern in this work is to simulate the EOF through nanochannels considering both non-Newtonian fluid properties and non-continuum flow conditions. We have chosen DPD as our working tool because...