scholarly journals MHD effect on nanofluid with energy and hydrothermal behavior between two collateral plates: Application of new semi analytical technique

2017 ◽  
Vol 21 (5) ◽  
pp. 2081-2093 ◽  
Author(s):  
Mohsen Sheikholeslami ◽  
Akbar Sher ◽  
Muhammad Mustafa

In this study, heat and mass transfer characteristic of unsteady nanofluid flow between parallel plates is investigated. The important effect of Brownian motion and thermophoresis has been included in the model of nanofluid. The governing equations are solved via differential transformation method. The validity of this method was verified by comparison previous work which is done for viscous fluid. The analytical investigation is carried out for different governing parameters namely: the squeeze number, Hartmann number, Schmidt number, Brownian motion parameter, thermophoretic parameter, and Eckert number. The results indicate that skin friction coefficient has direct relationship with Hartmann number and squeeze number. Also it can be found that Nusselt number increases with increase of Hartmann number, Eckert number, and Schmidt number but it is decreases with augment of squeeze number.

Heat transfer behavior of unsteady flow of squeezing nanofluid (Copper+water) between two parallel plates is investigated. By using the appropriate transformation for the velocity and temperature, the basic equations governing the flow and heat transfer were reduced to a set of ordinary differential equations. These equations subjected to the associated boundary conditions were solved analytically using Homotopy Perturbation Method and numerically using Runge-Kutta-Fehlberg method with shooting technique. Effects on the behavior of velocity and temperature for various values of relevant parameters are illustrated graphically. The skin-friction coefficient, heat transfer and Nusselt number rate are also tabulated for various governing parameters. The results indicate that, for nanofluid flow, the rates of heat transfer and velocity had direct relationship with squeeze number and nanoparticle volume fraction they are also a decreasing function of those parameters


2019 ◽  
Vol 142 (1) ◽  
Author(s):  
R. A. Mohamed ◽  
S. Z. Rida ◽  
A. A. M. Arafa ◽  
M. S. Mubarak

Abstract In this paper, the influence of chemical reaction and heat source/sink on an unsteady magnetohydrodynamics (MHD) nanofluid flow that squeezed between two radiating parallel plates embedded in porous media is investigated analytically. We consider water as base fluid and aluminum oxide (Al2O3) as its nanoparticle. We reduced the basic partial differential equations to ordinary differential equations which are solved by the homotopy analysis method (HAM). The effects of the squeeze number, permeability parameter of porous media, Hartmann number, thermal radiation parameter, Prandtl number, heat source/sink parameter, Eckert number, Schmidt number, and scaled parameter of chemical reaction on the flow, heat, and mass transfer are considered and assigned to graphs. The physical quantities such as Sherwood number, Nusselt number, and skin friction coefficient are computed for Al2O3–water, TiO2–water, Ag–water, and Cu–water nanofluids and assigned through graphs.


2017 ◽  
Vol 21 (5) ◽  
pp. 2057-2067 ◽  
Author(s):  
Mohammad Rahimi-Gorji ◽  
Oveis Pourmehran ◽  
Mofid Gorji-Bandpy ◽  
Davood Ganji

This paper presents a thermal and flow analysis of an unsteady squeezing nanofluid flow and heat transfer using nanofluid based on Brinkman model in presence of variable magnetic field. Galerkin method is used to solve the non-linear differential equations governing the problem. Squeezing flow between parallel plates is very applicable in the many industries and it means that one or both of the parallel plates have vacillation. The effects of active parameters such as the Hartman number, squeeze number, and heat source parameter are discussed. Results for temperature distribution and velocity profile, Nusselt number, and skin friction coefficient by Galerkin method are presented. As can be seen in results, the values of Nusselt number and skin friction coefficient for CuO is better than Al2O3. Also, according to figures, as nanofluid volume fraction increases, Nusselt number increases and skin friction coefficient decreases, increase in the Hartman number results in an increase in velocity and temperature profiles and an increase in squeeze number can be associated with the decrease in the velocity. <br><br><font color="red"><b> This article has been corrected. Link to the correction <u><a href="http://dx.doi.org/10.2298/TSCI171204246E">10.2298/TSCI171204246E</a><u></b></font>


Symmetry ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 1367 ◽  
Author(s):  
Alias Jedi ◽  
Noorhelyna Razali ◽  
Wan Mohd Faizal Wan Mahmood ◽  
Nor Ashikin Abu Bakar

In this study, the heat and mass transfer characteristics of nanofluid flow over a nonlinearly stretching sheet are investigated. The important effects of axisymmetric of thermal conductivity and viscous dissipation have been included in the model of nanofluids. The Buongiorno model is considered to solve the nanofluid boundary layer problem. The governing nonlinear partial differential equations have been transformed into a system of ordinary differential equations and are solved numerically via the shooting technique. The validity of this method was verified by comparison with previous work performed for nanofluids without the effects of the magnetic field and viscous dissipation. The analytical investigation is carried out for different governing parameters, namely, the Brownian motion parameter, thermophoresis parameter, magnetic parameter, Biot number, and Eckert number. The results indicate that the skin friction coefficient has a direct relationship with the Brownian motion number and thermophoresis number. Moreover, it can be seen that the Nusselt number decreases with the increase of the magnetic parameter and Eckert number.


Author(s):  
Binyam Zigta

In this paper the effect of unsteady, incompressible, magneto hydrodynamics filled with electrically conducting viscoelastic fluid in an infinite vertical Couette porous channel wall embedded in a porous medium is analyzed. A uniform magnetic field is applied perpendicular to the channel wall. The temperature of the moving channel wall varies periodically and the temperature difference between the two infinite vertical channel walls is high due to thermal radiation. The Eckert number is the ratio of the kinetic energy of the flow to the temperature difference of the channel walls. The solution of the governing equations is obtained using regular perturbation techniques. These techniques are used to transform partial differential equations that are difficult to solve in closed form. These equations are reduced to a set of ordinary differential equations in dimensionless form so can be solved analytically. The effects of physical parameters Viz. Hartmann number, Viscoelastic parameter, Eckert number, Permeability of porous medium, Chemical reaction parameter, thermal Grashof number for heat transfer, modified Grashof number for mass transfer, frequency parameter and Schmidt number on flow parameters Viz., velocity, temperature and concentration has been discussed and shown graphically. The theoretical results have been supported by MATLAB code simulation study. The results show that velocity decreases with increasing values of frequency, Hartmann number and viscoelastic parameter but reverse effect is observed with temperature, thermal Grashof number, modified Grashof number and permeability of porous medium. Furthermore, The result shows that an increment in both thermal radiation parameter and Eckert number results in decrement of temperature near the moving porous channel wall while it approaches to a zero in the region close to the boundary layer of the stationary channel wall,. An increment in both chemical reaction and Schmidt number results in decreasing concentration. The velocity of fluid increases as Grashof number and modified Grashof number increases.


2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Khilap Singh ◽  
Sawan K. Rawat ◽  
Manoj Kumar

Heat and mass transfer behavior of unsteady flow of squeezing nanofluids between two parallel plates in the sight of uniform magnetic field with slip velocity effect is investigated. The governing equations representing fluid flow have been transformed into nonlinear ordinary differential equations using similarity transformation. The equations thus obtained have been solved numerically using Runge-Kutta-Fehlberg method with shooting technique. Effects on the behavior of velocity, temperature, and concentration for various values of relevant parameters are illustrated graphically. The skin-friction coefficient and heat and mass transfer rate are also tabulated for various governing parameters. The results indicate that, for nanofluid flow, the rates of heat and mass transfer are inversely proportional to nanoparticle volume fraction and magnetic parameter. The rate of mass transfer increases with increasing values of Schmidt number and squeeze number.


2020 ◽  
Vol 9 (1) ◽  
pp. 201-222 ◽  
Author(s):  
Usha Shankar ◽  
Neminath B. Naduvinamani ◽  
Hussain Basha

AbstractPresent research article reports the magnetized impacts of Cattaneo-Christov double diffusion models on heat and mass transfer behaviour of viscous incompressible, time-dependent, two-dimensional Casson nanofluid flow through the channel with Joule heating and viscous dissipation effects numerically. The classical transport models such as Fourier and Fick’s laws of heat and mass diffusions are generalized in terms of Cattaneo-Christov double diffusion models by accounting the thermal and concentration relaxation times. The present physical problem is examined in the presence of Lorentz forces to investigate the effects of magnetic field on double diffusion process along with Joule heating. The non-Newtonian Casson nanofluid flow between two parallel plates gives the system of time-dependent, highly nonlinear, coupled partial differential equations and is solved by utilizing RK-SM and bvp4c schemes. Present results show that, the temperature and concentration distributions are fewer in case of Cattaneo-Christov heat and mass flux models when compared to the Fourier’s and Fick’s laws of heat and mass diffusions. The concentration field is a diminishing function of thermophoresis parameter and it is an increasing function of Brownian motion parameter. Finally, an excellent comparison between the present solutions and previously published results show the accuracy of the results and methods used to achieve the objective of the present work.


Author(s):  
A Mahdy ◽  
GA Hoshoudy

The present exploration addresses the boundary layer electro-magnetohydrodynamic (EMHD) flow of time-dependant non-Newtonian tangent hyperbolic nanofluid that is electrically conducting past a Riga surface with variable thickness and slip boundary condition. Configuration flow modeling is deduced considering chemical reaction and heat generation/absorption with the impacts of Brownian motion and thermophoresis. Also a newly proposed boundary condition with zero mass flux has been presented in the current contribution. Numerical solution of the governing non-linear differential equations is presented by considering the shooting technique. Graphical illustrations pointing out the aspects of distinct physical parameters on the non-Newtonian nanofluid velocity, temperature and concentration fields are introduced. From the computational results, the concentration distribution gives a decreasing function of the chemical reaction and Brownian motion parameters. Higher values of shape parameter yield a negative influence on the mechanical properties of the surface. The Hartmann number leads to maximize both of velocity field and skin friction coefficient. Additionally, numerical computed values of the skin friction, local Nusselt and Sherwood numbers are depicted with the needful discussion.


2018 ◽  
Vol 141 (1) ◽  
Author(s):  
M. Farooq ◽  
S. Ahmad ◽  
M. Javed ◽  
Aisha Anjum

In this attempt, melting heat transfer characteristic of unsteady squeezed nanofluid flows in non-Darcy porous medium is interrogated. The nanofluid model incorporates Brownian diffusion and thermophoresis to characterize the heat and mass transport in the presence of thermal and solutal stratification. Similarity solutions are implemented to acquire nonlinear system of ordinary differential equations which are then evaluated using Homotopic technique. Flow behavior of involved physical parameters is examined and explanations are stated through graphs. We determine and analyze skin friction coefficient, Nusselt and Sherwood numbers through graphs. It is evident that larger melting parameter results in decrement in temperature field, while horizontal velocity enhances for higher melting parameter. Moreover, temperature and concentration fields are dominant for higher Brownian diffusion parameter.


2020 ◽  
Vol 34 (13) ◽  
pp. 2050130 ◽  
Author(s):  
Salman Ahmad ◽  
M. Ijaz Khan ◽  
T. Hayat ◽  
A. Alsaedi

Main objective of this paper is to investigate comparative analysis of Copper-water and Copper Oxide-Water nanofluids flow due to a stretchable plate. Magnetic field is applied in transverse direction. Energy equation contains impacts of viscous dissipation and Joule heating. Appropriate dimensionless variables are used to transform the nonlinear PDEs system into dimensionless form. The dimensionless PDEs system is solved numerically by FDM (Finite difference method). Impacts of flow variables including Reynolds number, nanoparticles fraction, Hartmann number and Eckert number on velocity, surface drag force, Nusselt number and temperature are analyzed. Obtained outcomes show that velocity increases through Reynolds number and time while it decreases with Hartmann number. Temperature enhances with Eckert number while it decays with time. Skin friction increases for both Hartmann number and Reynolds number. Nusselt number decreases through nanopartical fraction. Comparative analysis of Copper-water and Copper Oxide-Water nanofluids shows that velocity and temperature are higher in Copper-water when compared with Copper Oxide-Water. For higher nanopartical fraction, the velocity and temperature decrease.


Sign in / Sign up

Export Citation Format

Share Document