Unsteady MHD Flow of Radiating and Rotating Fluid with Hall Current and Thermal Diffusion Past a Moving Plate in a Porous Medium

2018 ◽  
Vol 389 ◽  
pp. 71-85
Author(s):  
Oluwole Daniel Makinde ◽  
Venkateswarlu Malapati ◽  
R.L. Monaledi
Keyword(s):  
Porous Medium ◽  
Hall Current ◽  
Chemical Species ◽  
Mhd Flow ◽  
Skin Friction Coefficient ◽  
Fluid Temperature ◽  
Species Concentration ◽  
Moving Plate ◽  
Laplace Transform Technique ◽  
Layer Flow

The paper examines the combined effects of Hall current, buoyancy forces, thermal radiation, thermo-diffusion and fluid rotation on an unsteady hydromagmetic boundary layer flow with heat and mass transfer over an impulsively moving vertical plate embedded in a porous medium. Base on some realistic simplified assumptions, the governing equations of momentum, energy and chemical species concentration are obtained and tackled analytically using Laplace transform technique. The numerical values of primary and secondary fluid velocities, fluid temperature and species concentration are displayed graphically while those of skin friction coefficient, Nusselt number and Sherwood number are presented in tabular form for different values of pertinent flow parameters.

scholarly journals Hall Current and Thermal Radiation Effects on Heat and Mass Transfer of Unsteady MHD Flow of a Viscoelastic Micropolar Fluid through a Porous Medium

2020 ◽  
Vol 68 (1) ◽  
pp. 1-10
Author(s):  
Lavanya
Keyword(s):  
Mass Transfer ◽  
Porous Medium ◽  
Thermal Radiation ◽  
Micropolar Fluid ◽  
Radiation Effects ◽  
Hall Current ◽  
Perturbation Technique ◽  
Mhd Flow ◽  
Skin Friction Coefficient ◽  
Governing Equations

The present paper is concerned to analyze the effect of hall current on heat and thermal radiation and mass transfer of unsteady MHD flow of a viscoelastic micropolar fluid through a porous medium with chemical reaction. The governing partial differential equations are transformed to dimensionless equations using dimensionless variables. The dimensionless governing equations are then solved analytically using perturbation technique. The effects of various governing parameters on the velocity, temperature, concentration, skin-friction coefficient, Nusselt number and Sherwood number are shown in figures and tables and analyzed in detail.

On the Analytic Solution of Magnetohydrodynamic (MHD) Flow by a Moving Wedge in Porous Medium

2018 ◽  
Vol 389 ◽  
pp. 128-137 ◽  
Author(s):  
Hamza Berrehal ◽  
Abdelaziz Maougal ◽  
Tasawar Hayat ◽  
Ahmed Alsaedi
Keyword(s):  
Porous Medium ◽  
Nonlinear Boundary ◽  
Mhd Flow ◽  
Skin Friction Coefficient ◽  
Governing Equations ◽  
Third Order ◽  
Moving Wedge ◽  
Optimal Homotopy Asymptotic Method ◽  
Layer Flow ◽  
Similarity Method

This paper is devoted to find analytic approximate solution by optimal homotopy asymptotic method (OHAM) for the problem of nonlinear boundary layer flow. Two-dimensional magneto-hydrodynamic (MHD) flow of a viscous fluid over a moving wedge in porous medium with suction/injection is investigated. Governing equations are transformed by similarity method into a third order Falkner-Skan equation and solved analytically using OHAM. This approach is highly efficient, ensuring a very rapid convergence of the solution only after one iteration. Graphical results are presented to discuss the effects of various parameters on velocity profiles. Further, the skin friction coefficient is also tabulated and compared with the corresponding results available in literature. Our results were found in an excellent agreement.

Soret and Dufour Effects on Hydromagnetic Flow of H2O-Based Nanofluids Induced by an Exponentially Expanding Sheet Saturated in a Non-Darcian Porous Medium

2021 ◽  
Vol 10 (4) ◽  
pp. 506-517
Author(s):  
A. K. Singha ◽  
G. S. Seth ◽  
Krishnendu Bhattacharyya ◽  
Dhananjay Yadav ◽  
Ajeet Kumar Verma ◽  
...  
Keyword(s):  
Porous Medium ◽  
Soret Effect ◽  
Flow Distribution ◽  
Mhd Flow ◽  
Skin Friction Coefficient ◽  
Hydromagnetic Flow ◽  
Species Concentration ◽  
Soret And Dufour Effects ◽  
Dufour Effect ◽  
Coupled Equations

Diffusion-thermo effect (Dufour effect) and thermal-diffusion effect (Soret effect) on an MHD flow through porous medium taking nanoparticles may be considered to be useful in many engineering problems when there is a species concentration along with the solid nanoparticles. To study such an attracting problem, it is necessary to consider the flow to be single-phase. In the present investigation, the hydromagnetic flow of H2O-based nanofluids due to an exponentially expanding sheet saturated in non-Darcian porous material is examined with Dufour and Soret effects. In addition, temperature and species concentration along the surface in flow distribution are considered to be variable exponentially. Two sorts of nanofluids are considered, to be specific, Cu–H2O and Ag–H2O. Use of proper similarity transformations transfers the governing PDEs to coupled ODEs. Then the solutions of the coupled equations are computed by very efficient shooting method. Non-dimensionless velocity species concentration and temperature are introduced in graphical mode for several values of involved parameters. Out of several obtained outcomes, it is noticeable that similar to the magnetic parameter and permeability parameter, due to increase in non-Darcy Forchheimer parameter velocity diminishes and while temperature and species concentration increments are witnessed. Due to presence of Dufour effect, temperature enhances and similarly, the concentration increases for Soret effect. While due to Dufour effect, the concentration initially decreases, but away from surface it increases and similar behaviour is found for temperature in the case of Soret effect. Also, it is obtained that skin-friction coefficient for Cu–H2O nanofluid is larger than it value for Ag–H2O nanofluid. Dufour effect turns into the reason for the reduction of Nusselt number and increment of Sherwood number for both nanofluids, but Soret effect affects the two nanofluids reversely. The analysis and its findings provide some tools which may be applied in engineering and industrial problems.

Magnetohydrodynamic Mixed-Convective Flow and Heat and Mass Transfer Past a Vertical Plate in a Porous Medium With Constant Wall Suction

2008 ◽  
Vol 130 (11) ◽  
Author(s):  
O. D. Makinde ◽  
P. Sibanda
Keyword(s):  
Heat Transfer ◽  
Porous Medium ◽  
Vertical Plate ◽  
Skin Friction Coefficient ◽  
Convection Flow ◽  
Convection Boundary Layer ◽  
Flow Equations ◽  
Schmidt Numbers ◽  
Layer Flow ◽  
Mixed Convective Flow

The problem of steady laminar hydromagnetic heat transfer by mixed convection flow over a vertical plate embedded in a uniform porous medium in the presence of a uniform normal magnetic field is studied. Convective heat transfer through porous media has wide applications in engineering problems such as in high temperature heat exchangers and in insulation problems. We construct solutions for the free convection boundary-layer flow equations using an Adomian–Padé approximation method that in the recent past has proven to be an able alternative to the traditional numerical techniques. The effects of the various flow parameters such as the Eckert, Hartmann, and Schmidt numbers on the skin friction coefficient and the concentration, velocity, and temperature profiles are discussed and presented graphically. A comparison of our results with those obtained using traditional numerical methods in earlier studies is made, and the results show an excellent agreement. The results demonstrate the reliability and the efficiency of the Adomian–Padé method in an unbounded domain.

scholarly journals Effects of Viscous and Joules Dissipation on MHD Flow, Heat and Mass Transfer past a Stretching Porous Surface Embedded in a Porous Medium

2009 ◽  
Vol 14 (3) ◽  
pp. 303-314 ◽  
Author(s):  
S. P. Anjali Devi ◽  
B. Ganga
Keyword(s):  
Porous Medium ◽  
Magnetic Parameter ◽  
Transverse Velocity ◽  
Longitudinal Velocity ◽  
Mhd Flow ◽  
Analytic Solutions ◽  
Skin Friction Coefficient ◽  
Porous Surface ◽  
Suction Parameter ◽  
Confluent Hypergeometric Functions

This paper investigates the influence of both viscous and joules dissipation on the problem of magnetohydrodynamic flow past a stretching porous surface embedded in a porous medium. Analytic solutions of the resulting nonlinear non-homogeneous boundary value problem in the case when the plate stretches with a velocity varying linearly with distance, expressed in terms of confluent hypergeometric functions, are presented for the case of prescribed surface temperature. Numerical calculations have been carried out for various values of suction parameter, magnetic field, Prandtl number, Eckert number and Schmidt number. The results show that increases in magnetic parameter decrease both the dimensionless transverse velocity, longitudinal velocity and also the skin friction coefficient. Also, formation of thin boundary layer is observed for higher value of magnetic parameter.

NATURAL CONVECTION BOUNDARY LAYER FLOW ALONG A SPHERE EMBEDDED IN A POROUS MEDIUM FILLED WITH A NANOFLUID

2014 ◽  
Vol 44 (2) ◽  
pp. 149-157
Author(s):  
A. M. RASHAD
Keyword(s):  
Boundary Layer ◽  
Porous Medium ◽  
Boundary Layer Flow ◽  
Volume Fraction ◽  
Skin Friction Coefficient ◽  
Convection Boundary Layer ◽  
Physical Parameters ◽  
Extended Model ◽  
Local Skin ◽  
Layer Flow

 A boundary-layer analysis is presented for the natural convec tion boundary layer flow about a sphere embedded in a porous medium filled with a nanofluid using Brinkman-ForchheimerDarcy extended model. The model used for the nanofluid incorporates the ef fects of Brownian motion and thermophoresis. The governing partial differential equa tions are transformed into a set of nonsimilar equations and solved numerically by an efficient implicit, iterative, finite-difference method. Comparisons with previously published work are performed and excellent agreement is obtained. A parametric study of the physical parameters is conducted and a representative set of numerical results for the velocity, temperature, and nanoparticles volume fraction profiles as well as the local skin-friction coefficient, local Nusselt and Sherwood numbers is illustrated graphically to show interesting features of the solutions.

scholarly journals Effect of joule heating and hall current on MHD flow of a Nanofluid due to a rotating disk with viscous dissipation

2018 ◽  
Vol 22 (2) ◽  
pp. 857-870 ◽  
Author(s):  
Mohamed Abdel-Wahed ◽  
Tarek Emam
Keyword(s):  
Boundary Layer ◽  
Constant Velocity ◽  
Hall Current ◽  
Similarity Transformation ◽  
Mhd Flow ◽  
Rotating Disk ◽  
Transformation Method ◽  
Temperature Profiles ◽  
Optimal Homotopy Asymptotic Method ◽  
Layer Flow

The present work provides an analysis of the hydromagnetic nanofluid boundary-layer flow over a rotating disk in a porous medium with a constant velocity in the presence of hall current and thermal radiation. The governing PDE system that describes the problem is converted to a system of ODE by the similarity transformation method, which solved analytically using optimal homotopy asymptotic method. The velocity profiles and temperature profiles of the boundary-layer are plotted and investigated in details. Moreover, the surface skin friction, rate of heat transfer are deduced and explained in details.

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