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Newtonian and generalized Newtonian reacting flows in serpentine microchannels: pressure driven and centrifugal microfluidics
, Article Journal of Non-Newtonian Fluid Mechanics ; Volume 251 , January , 2018 , Pages 88-96 ; 03770257 (ISSN) ; Shamloo, A ; Sharif University of Technology
Elsevier B.V
2018
Abstract
This paper presents a comprehensive 3D numerical simulation of reacting flows in micro scale dimension through centrifugal, or Lab-On-a-CD (LOCD), and pressure-driven, or Lab-On-a-Chip (LOC) devices. Three different serpentine channel configurations (rectangular, triangular and sinusoidal) are investigated. In these configurations, two chemical species enter from two inlets and according to an irreversible chemical reaction, start yielding other species. Both Newtonian and generalized Newtonian fluids are considered in the simulations and the results are compared for both LOC and LOCD devices. Besides, the effects of different parameters such as the aspect ratio of channels’ cross section,...
Application of the homotopy method for analytical solution of non-Newtonian channel flows
, Article Physica Scripta ; Volume 79, Issue 6 , 2009 ; 00318949 (ISSN) ; Kharazmi, S ; Farjami, Y ; Sharif University of Technology
2009
Abstract
This paper presents the homotopy series solution of the Navier-Stokes and energy equations for non-Newtonian flows. Three different problems, Couette flow, Poiseuille flow and Couette-Poiseuille flow have been investigated. For all three cases, the nonlinear momentum and energy equations have been solved using the homotopy method and analytical approximations for the velocity and the temperature distribution have been obtained. The current results agree well with those obtained by the homotopy perturbation method derived by Siddiqui et al (2008 Chaos Solitons Fractals36 182-92). In addition to providing analytical solutions, this paper draws attention to interesting physical phenomena...
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...
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,...
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...
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...
The Study of the Effect of Surfactant on the Liquid Drop Motion In Fluid
, M.Sc. Thesis Sharif University of Technology ; Firoozabadi, Bahar (Supervisor) ; Afshin, Hossein (Co-Supervisor)
Abstract
The drop motion in fluid and the mass transfer is one of the most interesting and favorite topics that has attracted the attention of many researchers. Knowing the functions of the factors affecting the deformation and the process of mass transfer and the effects of the addition of the surfactant, improve the efficiency of the related industrial processes.In this regard, the present study examines how the shape and speed of a moving Newtonian drop in a Newtonian fluid, the mass transfer of soluble material from inside the drop to the surrounding fluid and also the study of the effect of surfactant on the dynamics of moving droplet is studied numerically. During the drop movement, the...
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...
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...
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...
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...
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...
Simulating Structure Formation in Modified Newtonian Dynamics
, M.Sc. Thesis Sharif University of Technology ; Rahvar, Sohrab (Supervisor)
Abstract
We simulated the structure formation in the context of Modified Newtonian Dynamics with the spherical collapse model. We supposed a spherical region with mass of galactic order, positive density contrast and uniform distribution of matter as the initial condition and investigated the evolution of its internal regions, containing different amounts of matter. We began the simulation when the region was in Newtonian regime. The overdense region, which expands with cosmic fluid in Newtonian regime, gradually enters MONDian regime and gets separated from the background due to its stronger central acceleration; then it collapses and virializes after some swings. The density distribution of the...