Loading...
Search for:
non-newtonian
0.012 seconds
Total 85 records
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...
On the motion of Newtonian and non-Newtonian liquid drops
, Article Scientia Iranica ; Volume 19, Issue 5 , 2012 , Pages 1265-1278 ; 10263098 (ISSN) ; Maleki, A ; Firoozabadi, B ; Afshin, H ; Sharif University of Technology
2012
Abstract
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
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) ; Zadkazemi Derakhshi, A ; Nazari, A ; Firoozabadi, B ; Sharif University of Technology
Abstract
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...
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...
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) ; Sadeghi, A ; Saidi, M. H ; Sharif University of Technology
2011
Abstract
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...
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) ; Zakeri, R ; Schneider, G. E ; Sharif University of Technology
2010
Abstract
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...
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,...
Enhanced oil-in-water droplet generation in a T-junction microchannel using water-based nanofluids with shear-thinning behavior: A numerical study
, Article Physics of Fluids ; Volume 33, Issue 1 , 2021 ; 10706631 (ISSN) ; Shamloo, A ; Kazemzadeh Hannani, S ; Sharif University of Technology
American Institute of Physics Inc
2021
Abstract
Nanofluids are widely used as the continuous phase during droplet formation in microsystems due to their impressive features such as excellent thermal, magnetic, and interfacial properties. Although it is well-known that nanofluids are susceptible to exhibit non-Newtonian behavior even at a low concentration of nanoparticles, effects of non-Newtonian behavior of nanofluids have not been studied on droplet formation thus far. In this study, oil-in-water droplet formation with a relatively high viscosity ratio of the immiscible phases was studied numerically in a T-junction microchannel. To inspect the non-Newtonian effects of aqueous nanofluids on droplet formation, empirical data on the...
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) ; Sadeghi, A ; Saidi, M. S ; Sharif University of Technology
2013
Abstract
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...
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) ; Sadeghi, A ; Saidi, M. H ; Sharif University of Technology
Springer Verlag
2015
Abstract
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...
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...
Hydrothermal analysis of non-Newtonian fluid flow (blood) through the circular tube under prescribed non-uniform wall heat flux
, Article Theoretical and Applied Mechanics Letters ; Volume 12, Issue 4 , 2022 ; 20950349 (ISSN) ; Akbari, S ; Shafii, M. B ; Hosseinzadeh, K ; Sharif University of Technology
Elsevier Ltd
2022
Abstract
The present article aims to investigate the Graetz-Nusselt problem for blood as a non-Newtonian fluid obeying the power-law constitutive equation and flowing inside the axisymmetric tube subjected to non-uniform surface heat flux. After the flow field is determined by solving the continuity and the momentum equations, the energy equation is handled by employing the separation of variables method. The resulting Eigen functions and Eigen values are numerically calculated using MATLAB built-in solver BVP4C. The analysis is first conducted for the situation of constant heat flux and subsequently generalized to apply to the case of sinusoidal variation of wall heat flux along the tube length,...
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...
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) ; Samimi, S ; Sharif University of Technology
Taylor and Francis - Balkema
2015
Abstract
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,...
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) ; Ramazani S. A, A ; Hosseini Amoli, H ; Behrang, A ; Kamyabi, A ; Sharif University of Technology
2010
Abstract
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...
Investigation of wall shear stress related factors in realistic carotid bifurcation geometries and different flow conditions
, Article Scientia Iranica ; Volume 17, Issue 5 B , 2010 , Pages 358-366 ; 10263098 (ISSN) ; Jafarnejad, M ; Firoozabadi, B ; Saidi, M. S ; Sharif University of Technology
Abstract
Cardiovascular diseases are one of the major causes of death in the world; atherosclerosis being one aspect. Carotid bifurcation is one of the sites that are vulnerable to this disease. Wall Shear Stress (WSS) is known to be responsible for the process of atherogenesis. In this study, we have simulated the blood flow for Newtonian and non-Newtonian, steady and unsteady, flow conditions in three idealistic and five realistic geometries. A risk factor has been presented based on the results of wall shear stress and, then, a relation was found between geometrical features and the wall shear stress risk factor. Our main conclusions are: 1) The non-Newtonian behavior of blood elevates the value...
Phase behavior and rheology of emulsions in an alkaline/cosolvent/crude oil/brine system
, Article Petroleum Science and Technology ; Volume 34, Issue 3 , 2016 , Pages 207-215 ; 10916466 (ISSN) ; Hemmati, M ; Shariat Panahi, H ; Masihi, M ; Karam Beigi, M. S ; Sharif University of Technology
Taylor and Francis Inc
Abstract
Phase behavior of active crude oil/alkaline was systematically studied in the presence of cosolvents. For this purpose, several factors have been considered: alkaline concentration, oil concentration, and type of brine. The best composition was used to generate emulsion for rheology and displacement tests. Furthermore, precipitation of alkaline was eliminated by its synergy with EDTA. Next, rheology of emulsion was analyzed by which a Power law model was developed that indicates non-Newtonian behavior of emulsion. Moreover, the viscosity of emulsion was reduced by the addition of cosolvent as well as by the increase of alkaline concentration. Finally, the best formulation (containing...
Effects of Brownian motions and thermophoresis diffusions on the hematocrit and LDL concentration/diameter of pulsatile non-Newtonian blood in abdominal aortic aneurysm
, Article Journal of Non-Newtonian Fluid Mechanics ; Volume 294 , 2021 ; 03770257 (ISSN) ; Esfahani, A. N ; Golab, E ; Golestanian, O ; Ashouri, N ; Sajadi, S. M ; Ghaemi, F ; Baleanu, D ; Karimipour, A ; Sharif University of Technology
Elsevier B.V
2021
Abstract
LDL concentration is believed to be responsible for plaque formation that leads to atherosclerotic cardiovascular disease. We conducted this study to investigate the effects of hematocrits and LDL diameters on LDL concentration on the wall of an abdominal aortic aneurysm (AAA). The blood flow was considered to be a pulsatile and non-Newtonian flow whose viscosity was a function of hematocrits and strain rate. Lumen, Brownian, and thermophoresis diffusions were analyzed in LDL concentration. The results demonstrated that adding thermophoresis diffusion increases LDL concentration. Moreover, among three types of LDLs, including small LDLs, intermediate LDLs, and large LDLs, small LDLs were the...
Effects of Brownian motions and thermophoresis diffusions on the hematocrit and LDL concentration/diameter of pulsatile non-Newtonian blood in abdominal aortic aneurysm
, Article Journal of Non-Newtonian Fluid Mechanics ; Volume 294 , 2021 ; 03770257 (ISSN) ; Esfahani, A. N ; Golab, E ; Golestanian, O ; Ashouri, N ; Sajadi, S. M ; Ghaemi, F ; Baleanu, D ; Karimipour, A ; Sharif University of Technology
Elsevier B.V
2021
Abstract
LDL concentration is believed to be responsible for plaque formation that leads to atherosclerotic cardiovascular disease. We conducted this study to investigate the effects of hematocrits and LDL diameters on LDL concentration on the wall of an abdominal aortic aneurysm (AAA). The blood flow was considered to be a pulsatile and non-Newtonian flow whose viscosity was a function of hematocrits and strain rate. Lumen, Brownian, and thermophoresis diffusions were analyzed in LDL concentration. The results demonstrated that adding thermophoresis diffusion increases LDL concentration. Moreover, among three types of LDLs, including small LDLs, intermediate LDLs, and large LDLs, small LDLs were the...
Numerical Simulation of Heat Transfer on Topographically Structured Surfaces
, M.Sc. Thesis Sharif University of Technology ; Moosavi, Ali (Supervisor)
Abstract
Numerous three-dimensional models of laminar flow and heat transfer in rough microchannels are developed and analyzed numerically to compare the effect of roughness elements on the thermal and hydrodynamic characteristics. In these models, the rough surfaces are configured with rectangular, triangular and sinusoidal roughness elements. Here, the effects of the roughness height, roughness element width, roughness element pitch, channel separation, Reynolds number and both Newtonian and non-Newtonian fluid on pressure drop and heat transfer in rough microchannels are all investigated and discussed.H2 thermal boundary condition is considered for all peripheral walls and power law model also is...