Search for: non-newtonian-liquids
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    On the motion of Newtonian and non-Newtonian liquid drops

    , Article Scientia Iranica ; Volume 19, Issue 5 , 2012 , Pages 1265-1278 ; 10263098 (ISSN) Aminzadeh, M ; Maleki, A ; Firoozabadi, B ; Afshin, H ; Sharif University of Technology
    In the present study, the motion of Newtonian and non-Newtonian liquid drops has been investigated experimentally. In order to investigate the effect of bulk fluid on drops, we have used water and air, as two fluids with different properties, and various industrial and biological applications. Image processing is utilized to analyze the images obtained by a high speed camera. The research has been separated into two parts. The first part has been devoted to the experiments in which air is the bulk fluid, and the second is related to the experiment carried out in water. The range of Reynolds number is, approximately, 50

    Modeling and experimental investigation of bubble formation in shear-thinning liquids

    , Article Journal of Fluids Engineering, Transactions of the ASME ; Volume 139, Issue 7 , 2017 ; 00982202 (ISSN) Taghi Esfidani, M ; Reza Oshaghi, M ; Afshin, H ; Firoozabadi, B ; Sharif University of Technology
    American Society of Mechanical Engineers (ASME)  2017
    This investigation presents both theoretical and experimental studies on the size of a growing bubble in power-law non-Newtonian liquids. At first, some previous works on the prediction of bubble size in Newtonian liquids have been extended by considering the balance of forces acting on the bubble at the moment of separation. Predicted bubble sizes were validated against the experimental results for a wide range of operating conditions, including different gas flow rates and needle diameters as well as a wide range of physical properties of the Newtonian liquids. Furthermore, in order to determine the size of the bubbles formed in power-law non-Newtonian liquids with a similar analysis, the... 

    Thermal transport characteristics of non-newtonian electroosmotic flow in a slit microchannel

    , Article ASME 2011 9th International Conference on Nanochannels, Microchannels, and Minichannels, ICNMM 2011, 19 June 2011 through 22 June 2011 ; Volume 1 , June , 2011 , Pages 169-176 ; 9780791844632 (ISBN) Babaie, A ; Sadeghi, A ; Saidi, M. H ; Sharif University of Technology
    Electroosmosis has many applications in fluid delivery at microscale, sample collection, detection, mixing and separation of various biological and chemical species. In biological applications, most fluids are known to be non-Newtonian. Therefore, the study of thermal features of non-Newtonian electroosmotic flow is of great importance for scientific communities. In the present work, the fully developed electroosmotic flow of power-law fluids in a slit microchannel is investigated. The related equations are transformed into non-dimensional forms and necessary changes are made to adapt them for non-Newtonian fluids of power-law model. Results show that depending on different flow parameters... 

    3D simulation of propagation of hydraulically driven fractures in oil reservoirs using EFG mesh-less method considering coupled hydro-mechanical effects

    , Article Computer Methods and Recent Advances in Geomechanics - Proceedings of the 14th Int. Conference of International Association for Computer Methods and Recent Advances in Geomechanics, IACMAG 2014, 22 September 2014 through 25 September 2014, Kyoto ; September , 2015 , Pages 1675-1680 ; 9781138001480 (ISBN) Pak, A ; Samimi, S ; Sharif University of Technology
    Taylor and Francis - Balkema  2015
    Creating hydraulically induced fractures in oil/gas reservoirs is one of the methods for Enhanced Oil Recovery (EOR) that has been applied extensively in petroleum industry in recent years. Despite its popularity, the design process of Hydraulic Fracture treatment is mostly empirical based on the previous experiences gained in the oil-rich formation. The reason lies in the complexities involved in the Hydraulic Fracture process including interacting effects of fluid(s) flowand solid deformations, injection of non-Newtonian fluids in the porous media, leak-off of the injected fluid into the formation, complex geometry of the induced fracture in the intact or naturally fractured rock,... 

    DPD simulation of electroosmotic flow in nanochannels and the evaluation of effective parameters

    , Article 10th AIAA/ASME Joint Thermophysics and Heat Transfer Conference, 28 June 2010 through 1 July 2010, Chicago, IL ; 2010 ; 9781600867453 (ISBN) Darbandi, M ; Zakeri, R ; Schneider, G. E ; Sharif University of Technology
    We provide the simulation of electroosmotic phenomenon in nanochannels using the Dissipative Particle Dynamics (DPD) method. We study the electroosmotic phenomenon for both newtonian and non-newtonian fluids. Literature shows that most of past electroosmotic studies have been concentrated on continuum newtonian fluids. However, there are many nano/microfluidic applications, which need to be treated as either non-newtonian fluids or non-continuum fluids. In this paper, we simulate the electroosmotic flow in nanochannel considering no limit if it is neither continuum nor non-nonewtonian. As is known, the DPD method has several important advantages compared with the classical molecular dynamics... 

    Flow of a PTT fluid through planar contractions - Vortex inhibition using rounded corners

    , Article ASME 2010 International Mechanical Engineering Congress and Exposition, IMECE 2010, Vancouver, BC, 12 November 2010 through 18 November 2010 ; Volume 7, Issue PARTS A AND B , November , 2010 , Pages 601-607 ; 9780791844441 (ISBN) Khodadadi Yazdi, M ; Ramazani S. A, A ; Hosseini Amoli, H ; Behrang, A ; Kamyabi, A ; Sharif University of Technology
    Contraction flow is one of important geometries in fluid flow both in Newtonian and non-Newtonian fluids. In this study, flow of a viscoelastic fluid through a planar 4:1 contraction with rounded corners was investigated. Six different rounding ratios (RR =0, 0.125, 0.25, 0.375, 0.438, 0.475, 0.488) was examined using the linear PTT constitutive equation at creeping flow and isothermal condition. Then the resulting PDE set including continuity, momentum, and PTT constitutive equations were implemented to the OpenFOAM software. The results clearly show vortex deterioration with increasing rounding diameter, so that when rounding corner exceeds a critical value, the vortex disappears... 

    DPD simulation of non-Newtonian electroosmotic fluid flow in nanochannel

    , Article Molecular Simulation ; Volume 44, Issue 17 , 2018 , Pages 1444-1453 ; 08927022 (ISSN) Jafari, S ; Zakeri, R ; Darbandi, M ; Sharif University of Technology
    Taylor and Francis Ltd  2018
    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... 

    Computational inertial microfluidics: a review

    , Article Lab on a Chip ; Volume 20, Issue 6 , 2020 , Pages 1023-1048 Razavi Bazaz, S ; Mashhadian, A ; Ehsani, A ; Saha, S. C ; Krüger, T ; Ebrahimi Warkiani, M ; Sharif University of Technology
    Royal Society of Chemistry  2020
    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,... 

    Electrophoretic velocity of spherical particles in Quemada fluids

    , Article Colloids and Surfaces A: Physicochemical and Engineering Aspects ; Volume 436 , September , 2013 , Pages 225-230 ; 09277757 (ISSN) Moosavi, S. M ; Sadeghi, A ; Saidi, M. S ; Sharif University of Technology
    The biomicrofluidic devices utilizing electrophoresis for sample manipulation are usually encountered with non-Newtonian behavior of working fluids. Hence, developing theoretical models capable of predicting the electrophoretic velocity of colloidal particles in non-Newtonian fluids is of high importance for accurate design and active control of these devices. The present investigation is dealing with the electrophoresis of a spherical particle in a biofluid obeying the Quemada rheological model. The sphere radius is considered to be significantly larger than the Debye length. Moreover, it is assumed that the particle zeta potential is small so that the Debye-Hückel linearization is... 

    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) Babaie, A ; Saidi, M. H ; Sadeghi, A ; Sharif University of Technology
    Elsevier  2012
    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 depthwise averaging solution for cross-stream diffusion in a Y-micromixer by considering thick electrical double layers and nonlinear rheology

    , Article Microfluidics and Nanofluidics ; Volume 19, Issue 6 , 2015 , Pages 1297-1308 ; 16134982 (ISSN) Ahmadian Yazdi, A ; Sadeghi, A ; Saidi, M. H ; Sharif University of Technology
    Springer Verlag  2015
    Both nonlinear rheology and finite EDL thickness effects on the mixing process in an electroosmotically actuated Y-sensor are being investigated in this paper, utilizing a depthwise averaging method based on the Taylor dispersion theory. The fluid rheological behavior is assumed to obey the power-law viscosity model. Analytical solutions are obtained assuming a large channel width to depth ratio for which a 1-D profile can efficiently describe the velocity distribution. Full numerical simulations are also performed to determine the applicability range of the analytical model, revealing that it is able to provide accurate results for channel aspect ratios of ten and higher and quite... 

    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) Yousefian, Z ; Saidi, M. H ; Sharif University of Technology
    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) Shamloo, A ; Mirzakhanloo, M ; Dabirzadeh, M. R ; Sharif University of Technology
    Elsevier  2016
    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... 

    Transient analysis of falling cylinder in non-Newtonian fluids: further opportunity to employ the benefits of SPH method in fluid-structure problems

    , Article Chemical Product and Process Modeling ; Volume 12, Issue 1 , 2017 ; 21946159 (ISSN) Kamyabi, M ; Ramazani Saadat Abadi, A ; Kamyabi, A ; Sharif University of Technology
    Walter de Gruyter GmbH  2017
    Smoothed particle hydrodynamics (SPH) was applied to simulate the free falling of cylindrical bodies in three types of fluids including Newtonian, generalized-Newtonian and viscoelastic fluids. Renormalized derivation schemes were used because of their consistency in combination with the latest version of no slip boundary condition to improve the handling of moving fluid-structure interactions (FSIs). Verification of the method was performed through comparing the results of some benchmark examples for both single and two phase flows with the literature. The effects of some parameters such as the viscosity of the Newtonian fluid, the n index of the power-law fluid and the relaxation time of... 

    Drop formation from a capillary tube: comparison of different bulk fluid on newtonian drops and formation of newtonian and non-newtonian drops in air using image processing

    , Article International Journal of Heat and Mass Transfer ; Volume 124 , 2018 , Pages 912-919 ; 00179310 (ISSN) Nazari, A ; Zadkazemi Derakhshi, A ; Nazari, A ; Firoozabadi, B ; Sharif University of Technology
    The formation of water drops as a Newtonian fluid and formation of a shear-thinning non-Newtonian fluid, Carboxyl Methyl Cellulose (CMC) from a capillary into different bulk fluids are experimentally investigated. A high speed camera is used to visualize the images of the drops and an image-processing code employed to determine the drop properties from each image. It was found that the properties of the water drops when they are drooped into the liquids bulk fluids such as toluene and n-hexane are almost the same while they differed substantially when they were drooped into the air bulk fluid. It is shown that during the formation of water drop in all three kinds of bulk fluids, the drop... 

    Experimental investigation and comparison of Newtonian and non-Newtonian shear-thinning drop formation

    , Article Experimental Thermal and Fluid Science ; Volume 94 , 2018 , Pages 148-158 ; 08941777 (ISSN) Salehi, M. S ; Esfidani, M. T ; Afshin, H ; Firoozabadi, B ; Sharif University of Technology
    Elsevier Inc  2018
    The presence of small amount of polymer in Newtonian liquids affects the fluid behavior significantly and creates superficial differences between Newtonian and non-Newtonian drop formation. In the present study, Newtonian and non-Newtonian shear-thinning drop formation in air is examined experimentally and the geometrical parameters, such as drop elongation length, minimum neck diameter and current contact angle are studied for water, glycerin solutions (79, 89 and 94% w/w) and Carboxymethyl cellulose (CMC) solutions (0.5 to 1.5% w/w) drops. The results indicate that at initial stages of the drop growth, Newtonian and non-Newtonian liquids behave similarly. However, at the start of the... 

    Pressure drop reduction of power-law fluids in hydrophobic microgrooved channels

    , Article Physics of Fluids ; Volume 31, Issue 7 , 2019 ; 10706631 (ISSN) Javaherchian, J ; Moosavi, A ; Sharif University of Technology
    American Institute of Physics Inc  2019
    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) Oshaghi, M. R ; Shahsavari, M ; Afshin, H ; Firoozabadi, B ; Sharif University of Technology
    Elsevier Inc  2019
    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) Salehpour, A ; Abdolahi Sadatlu, M. A ; Sojoudi, A ; Sharif University of Technology
    Pleiades Publishing  2019
    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... 

    Controlled drug delivery using the magnetic nanoparticles in non-Newtonian blood vessels

    , Article Alexandria Engineering Journal ; 2020 Abu Hamdeh, N. H ; Bantan, R. A. R ; Aalizadeh, F ; Alimoradi, A ; Sharif University of Technology
    Elsevier B.V  2020
    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...