scholarly journals MHD PERISTALTIC SLIP FLOW OF CASSON FLUID AND HEAT TRANSFER IN CHANNEL FILLED WITH A POROUS MEDIUM

2018 ◽  
Vol 0 (0) ◽  
pp. 0-0
Author(s):  
O. D. Makinde ◽  
M. Gnaneswara Reddy
2016 ◽  
Vol 21 (2) ◽  
pp. 323-339
Author(s):  
P.K. Gaur ◽  
A.K. Jha ◽  
R. Sharma

Abstract A theoretical study is carried out to obtain an analytical solution of free convective heat transfer for the flow of a polar fluid through a porous medium with variable permeability bounded by a semi-infinite vertical plate in a slip flow regime. A uniform magnetic field acts perpendicular to the porous surface. The free stream velocity follows an exponentially decreasing small perturbation law. Using the approximate method the expressions for the velocity, microrotation, and temperature are obtained. Further, the results of the skin friction coefficient, the couple stress coefficient and the rate of heat transfer at the wall are presented with various values of fluid properties and flow conditions.


2021 ◽  
Vol 408 ◽  
pp. 33-49
Author(s):  
Lazarus Rundora

This article analyses the thermal decomposition in an unsteady MHD mixed convection flow of a reactive, electrically conducting Casson fluid within a vertical channel filled with a saturated porous medium and the influence of the temperature dependent properties on the flow. The fluid is assumed to be incompressible with the viscosity coefficient varying exponentially with temperature. The flow is subjected to an externally applied uniform magnetic field. The exothermic chemical kinetics inherent in the flow system give rise to heat dissipation. A technique based on a semi-discretization finite difference scheme and the shooting method is applied to solve the dimensionless governing equations. The effects of the temperature dependent viscosity, the magnetic field and other important parameters on the velocity and temperature profiles, the wall shear stress and the wall heat transfer rate are presented graphically and discussed quantitatively and qualitatively. The fluid flow model revealed flow characteristics that have profound ramifications including the increased heat transfer enhancement attributes of the reactive temperature dependent viscosity Casson fluid flow.


2018 ◽  
Vol 16 ◽  
pp. 120-139 ◽  
Author(s):  
N.S. Shashikumar ◽  
B.C. Prasannakumara ◽  
Bijjanal Jayanna Gireesha ◽  
Oluwole Daniel Makinde

The heat transfer and entropy generation in a MHD flow of Casson fluid through a porous microchannel with thermal radiation were investigated numerically. Combined effects of suction/injection, hydrodynamic slip, magnetic field and convective boundary condition on the heat transfer and entropy generation are studied. The dimensionless equations are solved numerically by using fourth-fifth-order Runge–Kutta integration method along with shooting technique. Moreover, influences of pertinent parameters on velocity, temperature and entropy generation were discussed in detail and illustrated graphically. Based on numerical results, we can see that, entropy generation rate increases with an increase in radiation parameter and Biot number. As Hartmann number increases, the entropy generation decreases at the both cooled and heated plates and increases at the centerline region of the microchannel.


Author(s):  
Mythili Durairaj ◽  
Sivaraj Ramachandran ◽  
Rashidi Mohammad Mehdi

Purpose The present investigation aims to deal with the study of unsteady, heat-generating/-absorbing and chemically reacting Casson fluid flow over a vertical cone and flat plate saturated with non-Darcy porous medium in the presence of cross-diffusion effects. Design/methodology/approach A numerical computation for the governing equations has been performed using implicit finite difference method of Crank–Nicolson type. Findings The influence of various physical parameters on velocity, temperature and concentration distributions is illustrated graphically, and the physical aspects are discussed in detail. Numerical results for average skin-friction, Nusselt number and Sherwood number are tabulated for the pertaining physical parameters. Results indicate that Soret and Dufour effects have notable influence on heat and mass transfer characteristics of the fluid when the temperature and concentration gradients are high. It is also observed that the consideration of heat generation/absorption plays a vital role in predicting the heat transfer characteristics of moving fluids. Research limitations/implications Consider a two-dimensional, unsteady, free convective flow of an incompressible Casson fluid over a vertical cone and a flat plate saturated with non-Darcy porous medium. The fluid properties are assumed to be constant except for density variations in the buoyancy force term. The fluid flow is moderate and the permeability of the medium is assumed to be low, so that the Forchheimer flow model is applicable. Practical implications The flow of Casson fluids (such as drilling muds, clay coatings and other suspensions, certain oils and greases, polymer melts and many emulsions), in the presence of heat transfer, is an important research area because of its relevance in the optimized processing of chocolate, toffee and other foodstuffs. Social implications In the heat and mass transfer investigations, the Casson fluid model is found to be accurately applicable in many practical situations in the wings of polymer processing industries and biomechanics, etc.; some prominent examples are silicon suspensions, suspensions of bentonite in water and lithographic varnishes used for printing inks. Originality/value The motivation of the present study is to bring out the effects of heat source/sink, Soret and Dufour effects on chemically reacting Casson fluid flow over a vertical cone and flat plate saturated with non-Darcy porous medium. The flow of Casson fluids (such as certain oils and greases, polymer melts and many emulsions) in the presence of heat transfer is an important research area because of its relevance in the optimized processing of chocolate, toffee and other foodstuffs. A numerical computation for the governing equations has been performed using implicit finite difference method of the Crank–Nicolson type.


2017 ◽  
Vol 377 ◽  
pp. 166-179 ◽  
Author(s):  
Oluwole Daniel Makinde ◽  
Lazarus Rundora

In the current paper, we investigate the thermal decomposition in an unsteady mixed convection flow of a reactive Casson fluid in a vertical channel filled with a saturated porous medium. The channel walls are assumed to be permeable with fluid injection through the left wall and suction out of the right wall. There is heat dissipation caused by exothermic chemical reaction within the flow system. The dimensionless form of the momentum and energy equations will be solved numerically using a semi-discretization finite difference method and a fourth order Runge-Kutta-Fehlberg integration scheme. The influence of the Casson fluid parameter, the buoyancy parameter, the porous medium shape parameter, the Eckert number, the suction/injection Reynolds number, Frank-Kamenetskii parameter and the Prandtl number on velocity and temperature profiles, skin friction and Nusselt number as well as the thermal stability criteria are presented graphically and discussed quantitatively. It is revealed that increasing the Casson fluid parameter enhances the flow velocity, the fluid temperature and the skin friction but has a diminishing effect on the wall heat transfer rate. The suction/injection Reynolds number, the porous medium shape parameter and the buoyancy parameter enhance the rate of heat transfer at the channel walls.


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