Semi-infinite Vertical Porous Plate Research Articles

UNSTEADY FREE-CONVECTION IN BINARY MIXTURE OF A BOUNDARY LAYER FLOW PAST A VERTICAL POROUS PLATE WITH RADIATIVE HEAT TRANSFER

The combined free convection dynamic boundary layer and thermal radiation boundary layer along a semi-infinite vertical porous plate with mass transfer has been analyzed. The chemical reaction for a very simple model of a binary reaction with Arrhenius activation energy is incorporated into the analysis. The fluid is considered to be gray, absorbing-emitting. Under such conditions, the coupled and unsteady non-linear momentum, energy and concentration equations of the combined layers are then made similar by introducing a time dependent length scale and by the usual method of similarity transformation. The similarity equations are then solved numerically by the method of superposition. The resulting velocity and t emperature distributions are shown graphically for different values of the parameters entering into the problem. The numerical values of the skin friction coefficient ( w ) and the Nusselt number (Nu ) are calculated and presented in a tabular form.

View the PDF document Oscillating plate temperature effects on mixed convection Flow past a semi infinite vertical Porous Plate (Short Communication)

effects on mixed convection flow past a semi-infinite vertical porous plate have been studied when the plate temperature oscillates about a non-zero mean. Only out-of-phase component of unsteady part of the temperature is shown graphically. The results show that there is always a phase-lead in the rate of heat transfer at small values of w.

EFFECTS OF TRANSVERSE MAGNETIC FIELD, PRANDTL NUMBER AND REYNOLDS NUMBER ON NON-DARCY MIXED CONVECTIVE FLOW OF AN INCOMPRESSIBLE VISCOUS FLUID PAST A POROUS VERTICAL FLAT PLATE IN A SATURATED POROUS MEDIUM

The effect of transverse magnetic field parameter (Hartmann number, Ha), Reynolds number (Re) and Prandtl number (Pr) on the mixed convection flow past a semi-infinite vertical porous plate in a non-Darcian porous medium with variable viscosity and porosity, viscous dissipation and fluid–solid thermal conductivity ratio in the presence of plate transpiration (lateral mass flux) is investigated theoretically and numerically using Keller's implicit finite difference scheme. It is shown that the Hartmann number acts as a retarding force and increases the momentum boundary layer thickness, analogous to the flow against a positive pressure gradient, simultaneously decreasing local skin friction (shear stress). The heat transfer rate is however enhanced by the magnetic field (for positive values of the Eckert number) since the fluid is heated and temperature gradients become reduced between the fluid and the plate, with important potential applications in MHD power generators, materials processing and geothermal systems containing electrically-conducting fluids. The effects of high velocity flow (larger Re) and different Prandtl numbers corresponding to different industrial and geophysical fluids on heat transfer are also discussed. © 1997 by John Wiley & Sons, Ltd.

Free and forced convection boundary layer flow through a porous medium with large suction

An analytical study is made of the free and forced convection boundary layer flow past a porous medium bounded by a semi-infinite vertical porous plate. Locally similar solutions are then obtained by a perturbation method for large suction. Solutions for the velocity and temperature distributions are shown graphically for various suction velocities and values of the driving parameter Gr/R, where Gr is the Grashof number and Re is the Reynolds number. The corresponding values of the skin friction coefficient and the Nusselt number are finally shown in tabular form.

The boundary-layer flow past a semi-infinite heated porous plate for a two-component plasma

The flow in the boundary layer past a semi-infinite vertical hot porous plate is investigated for a two-component plasma model when the suction at the plate is large. Employing asymptotic expansion procedure the velocity and temperature fields are computed in the presence of free convection currents and viscous dissipation heat. The results are compared with the case when the flow is flow ionized. It is observed that the assumption of a fully ionized situation overestimates the basic flow variables.

Combined free and forced convection flow through a porous medium

Local similarity solutions of the forced and free convection flow past a porous medium bounded by a semi-infinite vertical porous plate are obtained numerically.

Combined free and forced convection flow past a vertial porous plate

Local similarity solutions of the forced and free convection flow past a semi-infinite vertical porous plate have been obtained numerically. Velocity and temperature profiles are shown for air (Pr = 0.72) and for different values of Gr (Gr > 0, cooling of the plate and Gr<0, heating of the plate) (Grashof number), E (Eckert number) and fw (fw>0, suction, fw <0, injection). the effects of these parameters are discussed.

Variable viscosity effects on mixed convection heat and mass transfer along a semi-infinite vertical plate in the presence of chemical reaction and viscous dissipation

An analysis is carried out to study the viscous dissipation and variable viscosity effects on the flow, heat and mass transfer characteristics in a viscous fluid over a semi-infinite vertical porous plate in the presence of chemical reaction. The governing boundary layer equations are written into a dimensionless form by similarity transformations. The transformed coupled nonlinear ordinary differential equations are solved numerically by using the implicit finite difference method. The effects of different parameters on the dimensionless velocity, temperature, and concentration profiles are shown graphically. In addition, tabulated results for the local skin-friction coefficient, the local Nusselt number, and the local Sherwood number are presented and discussed.Keywords: Variable viscosity, Chemical Reaction, Viscous Dissipation, Finite difference method, Suction.

Dufour and Soret effects on steady MHD free convection and mass transfer fluid flow through a porous medum in a rotating system

The numerical studies are performed to examine the steady MHD free convection and mass transfer fluid flow through a continuously moving porous medium with thermal diffusion and diffusion thermo past a semi-infinite vertical porous plate in a rotating system. Impulsively started plate moving in its own plane is considered. With appropriate transformations the boundary layer equations are transformed into nonlinear ordinary differential equations. The local similarity solutions of the transformed dimensionless equations for the flow, heat and mass transfer characteristics are evaluated using shooting iteration technique. Numerical results are presented in the form of velocity, temperature and concentration within the boundary layer for different parameters entering into the analysis. Also the effects of the pertinent parameters on the local skin-friction coefficients and rate of heat transfer as well as rate of mass transfer in terms of the local Nusselt number and Sherwood number respectively are also discussed. Keywords: MHD free convection, porous medium, rotation effect, Dufour effect, Soret effect.DOI: 10.3329/jname.v4i1.915 Journal of Naval Architecture and Marine Engineering 4(2007) 43-55

Dufour and Soret effects on MHD free convective heat and mass transfer flow past a vertical porous flat plate embedded in a porous medium

A two-dimensional steady MHD free convection and mass transfer flow past a semi-infinite vertical porous plate in a porous medium has been studied numerically including the Dufour and Soret effects. The resulting momentum, energy and concentration equations are then made similar by introducing the usual similarity transformations. These similar equations are then solved numerically by using the Nachtsheim-Swigert shooting method along with Runge-Kutta sixth order integration scheme. The numerical results are displayed graphically showing the effects of various parameters entering into the problem. Finally, the local values of the skin-friction coefficient (Cf), Nusselt number (Nu) and Sherwood number (Sh) are also shown in tabular form. Keywords: MHD, Free convection, Vertical plate, Steady flow, Porous medium, Dufour effect, Soret effect. doi: 10.3329/jname.v2i1.2030 Journal of Naval Architecture and Marine Engineering 2(1)(2005) 55-65