Diffusion Foundations Vol. 16

Abstract: The purpose of this paper is to investigate steady two-dimensional laminar magnetohydrodynamic (MHD) flow of an incompressible Jeffrey fluid past over a linearly stretching sheet. The governing partial differential equations (PDEs) of continuity, momentum, energy and concentration are transformed into nonlinear coupled ordinary differential equations (ODEs) by using similarity transformations. Then the ODEs are solved by applying Runge-Kutta fourth order method accompanied with shooting technique. The effects of various physical parameters characterizing the flow phenomenon including Deborah number, ratio of relaxation to retardation times, magnetic parameter, porous parameter, Prandtl number, Eckert number, heat source / sink parameter, Schmidt number and chemical reaction parameter on dimensionless velocity, temperature and concentration profiles are analyzed. The numerical results are obtained and presented in graphs. The present results are compared with the earlier published results as a particular case.

Abstract: 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.

Abstract: This paper deals with the study of the heat and mass transfer characteristics of natural convection from a horizontalsurface embedded in a radiating fluid saturated porous medium. Similarity solutions for buoyancy induced heat and masstransfer from a horizontal surface, where the wall temperature and concentration are a power function of distance fromthe origin, are obtained by using an integral approach of Von Karman type. The effects of the governing parameters suchas buoyancy ratio, Lewis number, radiation parameter and the power-law exponent on local Nusselt and local Sherwoodnumbers have been investigated both numerically and graphically.

Abstract: Abstract: The combined effect of variable viscosity and thermal conductivity on dissipative flow of oil-based nanofluid over a permeable vertical plate with suction has been studied. The governing partial differential equations have been transformed into a coupled third-order ordinary differential equations using similarity techniques. The resulting third-order ordinary differential equations were then reduced into a system of first-order ordinary differential equations and solved numerically using the fourth-order Runge-Kutta algorithm with a shooting method. The results revealed that both viscosity and thermal conductivities of CuO oil-based nanofluid enhances the intensity of the skin friction coefficient and the rate of heat transfer at the surface of the plate. Furthermore, the thermal boundary layer thickness is weakened by the viscosity of CuO oil-based nanofluid, the Prandtl number, the suction parameter, the permeability of the medium and the thermal Grashof number

Abstract: The present study deals with steady incompressible magneto hydrodynamic hyperbolic tangent fluid flow induced by a convectively heated stretching surface with the suspension of dust particles, Darcy-Forchheimer, thermal radiation, viscous dissipation and Ohmic heating. Similarity transformations were used to convert partial differential equations (PDEs) to a system of nonlinear ordinary differential equations (NODEs) which are solved numerically by Runge-Kutta Fehlberg method. The effect of pertinent parameters on velocity and temperature profiles of both fluid and dust phase within the boundary layer has been studied by considering various values of controlling parameters. Additionally, the skin friction coefficient and reduced heat transfer coefficient have been examined for various values of the governing parameters. It is found that Hartmann number and Forchheimer parameter reduce friction factor and heat transfer rates.