Islamic Azad University at Esfarayen

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Esfarayen, Iran
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Hatami M.,Islamic Azad University at Esfarayen | Hatami M.,University of Mazandaran | Ganji D.D.,University of Mazandaran
Journal of Molecular Liquids | Year: 2013

In this paper, heat transfer and flow analysis for a non-Newtonian nanofluid flow in the porous medium between two coaxial cylinders are investigated analytically and numerically. Sodium alginate (SA) is considered as the base non-Newtonian fluid and titanium dioxide (TiO2) nanoparticles are added to it. The viscosity of nanofluid is considered as a function of temperature by Reynolds model. Least Square Method (LSM), Collocation Method (CM) and fourth-order Runge-Kutta numerical method (NUM) are used to solve the present problem. The influences of the some physical parameters such as Brownian motion and thermophoresis parameters on non-dimensional velocity and temperature profiles are considered. The results show that increasing the thermophoresis parameter (Nt) caused an increase in temperature values in whole domain but it makes an increase in nanoparticle concentration near the inner cylinder wall. © 2013 Elsevier B.V.


Hatami M.,Babol Noshirvani University of Technology | Hatami M.,Islamic Azad University at Esfarayen | Sheikholeslami M.,Babol Noshirvani University of Technology | Sheikholeslami M.,University of Mazandaran | Ganji D.D.,Babol Noshirvani University of Technology
Journal of Molecular Liquids | Year: 2014

In this study, the least square method (LSM) and the Galerkin method (GM) are used to simulate flow and heat transfer of nanofluid flow between two parallel plates. One of the plates is externally heated, and the other plate, in which coolant fluid is injected through it, expands or contracts with time. The fluid in the channel is water containing different nanoparticles (Cu, Ag and Al2O3). The effective thermal conductivity and viscosity of the nanofluid are calculated by the Maxwell-Garnetts (MG) and Brinkman models, respectively. The effects of the nanoparticle volume fraction, Reynolds number, expansion ratio and power law index on flow and heat transfer are investigated. The results show that the Nusselt number increases with an increase of the nanoparticle volume fraction and Reynolds number. Also it can be found that in order to reach the maximum Nusselt number, copper should be used as a nanoparticle. © 2014 Elsevier B.V.


Sheikholeslami M.,University of Mazandaran | Sheikholeslami M.,Babol Noshirvani University of Technology | Hatami M.,Islamic Azad University at Esfarayen | Ganji D.D.,Babol Noshirvani University of Technology
Journal of Molecular Liquids | Year: 2014

In this paper the magnetohydrodynamic (MHD) nanofluid flow and heat transfer between two horizontal plates in a rotating system is analyzed. The lower plate is a stretching sheet and the upper one is a solid permeable plate. The basic partial differential equations are reduced to ordinary differential equations which are solved numerically using the fourth-order Runge-Kutta method. Different types of nanoparticles such as copper, silver, alumina and titanium oxide with water as their base fluid have been considered. Velocity and temperature profiles as well as the skin friction coefficient and the Nusselt number are determined numerically. The influence of pertinent parameters such as nanofluid volume fraction, magnetic parameter, wall injection/suction parameter, viscosity parameter and rotation parameter on the flow and heat transfer characteristics is discussed. The results indicate that, for both suction and injection the Nusselt number has a direct relationship with the nanoparticle volume fraction. The type of nanofluid is a key factor for heat transfer enhancement. The highest values are obtained when titanium oxide is used as a nanoparticle. Also it can be found that the Nusselt number decreases with the increase of the magnetic parameter due to the presence of Lorentz forces. © 2013 Elsevier B.V.


Hatami M.,Islamic Azad University at Esfarayen | Hatami M.,Babol Noshirvani University of Technology | Ganji D.D.,Islamic Azad University at Esfarayen
Particuology | Year: 2014

In this study, coupled equations of the motion of a particle in a fluid forced vortex were investigated using the differential transformation method (DTM) with the Padé approximation and the differential quadrature method (DQM). The significant contribution of the work is the introduction of two new, fast and efficient solutions for a spherical particle in a forced vortex that are improvements over the previous numerical results in the literature. These methods represent approximations with a high degree of accuracy and minimal computational effort for studying the particle motion in a fluid forced vortex. In addition, the velocity profiles (angular and radial) and the position trajectory of a particle in a fluid forced vortex are described in the current study. © 2014 Published by Elsevier B.V. on behalf of Chinese Society of Particuology and Institute of ProcessEngineering, Chinese Academy of Sciences.


Hatami M.,Islamic Azad University at Esfarayen | Hatami M.,University of Mazandaran | Hatami J.,Semnan University of Medical Sciences | Ganji D.D.,University of Mazandaran
Computer Methods and Programs in Biomedicine | Year: 2014

In this paper, heat transfer and flow analysis for a non-Newtonian third grade nanofluid flow in porous medium of a hollow vessel in presence of magnetic field are simulated analytically and numerically. Blood is considered as the base third grade non-Newtonian fluid and gold (Au) as nanoparticles are added to it. The viscosity of nanofluid is considered a function of temperature as Vogel's model. Least Square Method (LSM), Galerkin method (GM) and fourth-order Runge-Kutta numerical method (NUM) are used to solve the present problem. The influences of the some physical parameters such as Brownian motion and thermophoresis parameters on non-dimensional velocity and temperature profiles are considered. The results show that increasing the thermophoresis parameter (Nt) caused an increase in temperature values in whole domain and an increase in nanoparticles concentration just near the inner wall of vessel. Furthermore by increasing the MHD parameter, velocity profiles decreased due to magnetic field effect. © 2013 Elsevier Ireland Ltd.


Ahmadi A.R.,Islamic Azad University at Sari | Zahmatkesh A.,Islamic Azad University at Sari | Hatami M.,Islamic Azad University at Esfarayen | Ganji D.D.,University of Mazandaran
Powder Technology | Year: 2014

In the present paper, the unsteady flow and the related heat transfer of a nanofluid caused by linear motion of a horizontal flat plate has been analyzed and the nonlinear differential equations governing on the presented system have been reduced to a set of ordinary differential equations and obtained equations have been solved by Differential Transformation Method. Comparisons have been made between the obtained results and Runge-Kutta Numerical Solution, and the outcomes have been revealed that DTM is applicable in this case study. Furthermore, the relevant errors of the achieved solutions have been depicted graphically and these results indicate that the obtained analysis is trustable and applicable. It is necessary to mention that the effects of unsteadiness parameter S, Prandtl Number and finally volume fraction of the nanoparticles, φ on the temperature and velocity profile have been investigated. As a main outcome, the velocity profile is increased by enlarging the S parameter. Also, by increasing the φ, temperature profile has risen a lot which means the heat transfer properties can be enhanced by selecting appropriate nanoparticles sizes. © 2014 Elsevier B.V.


Hatami M.,Islamic Azad University at Esfarayen | Ganji D.D.,Babol Noshirvani University of Technology
Ceramics International | Year: 2014

In this study, heat transfer and temperature distribution equations for longitudinal convective-radiative porous fins are presented. It is assumed that the thickness of fins varies with length, so four different shapes (rectangular, convex, triangular and exponential) are considered. Temperature-dependent heat generation, convection and radiation are considered and heat transfer through porous media is simulated using passage velocity from Darcy's model. After deriving equation for all geometries, the Least Square Method (LSM) and fourth order Runge-Kutta method (NUM) are applied for predicting the temperature distribution in the porous fins. The selected ceramic porous materials are Al, SiC, and Si3N4. Effects of porosity, Darcy number, Rayleigh number, etc. on transferred heat are examined. As a main outcome, exponential section fin with Si3N4 material has the most amount of transferred heat among other shapes and materials. © 2013 Elsevier Ltd and Techna Group S.r.l.All rights reserved.


Hatami M.,Islamic Azad University at Esfarayen | Ganji D.D.,Babol Noshirvani University of Technology
Powder Technology | Year: 2014

In this letter, the equation of a particle's motion on a rotating parabolic surface is introduced through Lagrange equations and is solved by Multi-step Differential Transformation Method (Ms-DTM). As a main outcome, it is shown that this method gives approximations of a high degree of accuracy and least computational effort for studying particle motion on rotating parabolic surfaces compared to previous analytical methods. Also, position trajectory of the particle, r(t), and its phase planes are depicted in the current study for different constant numbers. © 2014 Elsevier B.V.


Hatami M.,Islamic Azad University at Esfarayen | Hatami M.,Babol Noshirvani University of Technology | Sheikholeslami M.,Babol Noshirvani University of Technology | Sheikholeslami M.,University of Mazandaran | Ganji D.D.,Babol Noshirvani University of Technology
Powder Technology | Year: 2014

In this study, asymmetric laminar flow and heat transfer of nanofluid between contracting rotating disks are investigated. The fluids in the channel are water containing different nanoparticles Cu, Ag and Al2O3. The effective thermal conductivity and viscosity of nanofluid are calculated by the Chon and Brinkman models, respectively. The governing equations are solved via the fourth-order Runge-Kutta-Fehlberg method (NUM) and least square method (LSM). The effects of the nanoparticle volume fraction, rotational Reynolds number, injection Reynolds number, expansion ratio and s on flow and heat transfer are considered. The results show that as s increases temperature profile increases and the point of maximum radial velocity is shifted towards the middle of the two disks. Also the results indicated that temperature profile becomes more flat near the middle of two disks with the increase of injection but opposite trend is observed with increase of expansion ratio. © 2014 Elsevier B.V.


Hatami M.,Islamic Azad University at Esfarayen | Hatami M.,University of Mazandaran | Ganji D.D.,University of Mazandaran
Case Studies in Thermal Engineering | Year: 2014

In this paper, natural convection of a non-Newtonian nanofluid flow between two vertical flat plates is investigated analytically and numerically. Sodium alginate (SA) is considered as the base non-Newtonian fluid, and then copper (Cu) and silver (Ag) as nanoparticles are added to it. The effective thermal conductivity and viscosity of nanofluid are calculated by Maxwell-Garnetts (MG) and Brinkman models, respectively. Least Square Method (LSM), Differential Transformation Method (DTM) and fourth-order Runge-Kutta numerical method (NUM) are used to solve the present problem. The influence of the some physical parameters such as nanofluid volume friction on non-dimensional velocity and temperature profiles is considered. The results show that Cu as nanoparticles makes larger velocity and temperature values for nanofluid compared to Ag. © 2013 The Authors.

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