scholarly journals Analytic Treatment for Electrical MHD Non-Newtonian Fluid Flow over a Stretching Sheet through a Porous Medium

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Gossaye Aliy Adem
Keyword(s):  
Magnetic Field ◽  
Porous Medium ◽  
Electric Field ◽  
Chemical Reaction ◽  
Internal Heat ◽  
Porous Matrix ◽  
Transverse Magnetic ◽  
Closed Form Solutions ◽  
Electrically Conducting ◽  
Boundary Layer Equations

In this study, an attempt has been made to investigate the mass and heat transfer effects in a BLF through a porous medium of an electrically conducting viscoelastic fluid subject to a transverse magnetic field in the existence of an external electric field, heat source/sink, and chemical reaction. It has been considered the effects of the electric field, viscous and Joule dissipations, radiation, and internal heat generation/absorption. Closed-form solutions for the boundary layer equations of viscoelastic, second-grade, and Walters’ B ′ fluid models are considered. The method of the solution includes similarity transformation. The converted equations of thermal and mass transport are calculated using the optimal homotopy asymptotic method (OHAM). The solutions of the temperature field for both prescribed surface temperature (PST) and prescribed surface heat flux (PHF) are found. It is vital to remark that the interaction of the magnetic field is found to be counterproductive in enhancing velocity and concentration distribution, whereas the presence of chemical reaction, as well as a porous matrix with moderate values of the magnetic parameter, reduces the temperature and concentration fields at all points of the flow domain.

scholarly journals Effect of radiation and porosity parameter on magnetohydrodynamic flow due to stretching sheet in porous media

2011 ◽  
Vol 15 (2) ◽  
pp. 517-526 ◽  
Author(s):  
Phool Singh ◽  
Tomer Singh ◽  
Sandeep Kumar ◽  
Deepa Sinha
Keyword(s):  
Magnetic Field ◽  
Heat Transfer ◽  
Stretching Sheet ◽  
Transverse Magnetic ◽  
Stream Velocity ◽  
Electrically Conducting ◽  
Boundary Layer Equations ◽  
Porosity Parameter ◽  
Volumetric Rate ◽  
Two Dimensional Flow

An analysis is made for the steady two-dimensional flow of a viscous incompressible electrically conducting fluid in the vicinity of a stagnation point on a stretching sheet. Fluid is considered in a porous medium under the influence of (i)transverse magnetic field, (ii)volumetric rate of heat generation/absorption in the presence of radiation effect. Rosseland approximation is used to model the radiative heat transfer. The governing boundary layer equations are transformed to ordinary differential equations by taking suitable similarity variables. In the present reported work the effect of porosity parameter, radiation parameter, magnetic field parameter and the Prandtl number on flow and heat transfer characteristics have been discussed. Variation of above discussed parameters with the ratio of free stream velocity parameter to stretching sheet parameter have been graphically represented.

Unsteady Squeezing Flow and Mass Transfer in a Channel with Temporal Width

2018 ◽  
Vol 389 ◽  
pp. 86-99
Author(s):  
Kanakalata L. Ojha ◽  
R.N. Barik ◽  
G.C. Dash
Keyword(s):  
Magnetic Field ◽  
Chemical Reaction ◽  
Transverse Magnetic ◽  
Integration Scheme ◽  
Squeezing Flow ◽  
Time Varying ◽  
Electrically Conducting ◽  
Similarity Transformations ◽  
Homotopy Analysis ◽  
Complex Boundary

An analysis is carried on an unsteady two-dimensional squeezing radiative flow of an incompressible, viscous, electrically conducting fluid in the presence of time-varying transverse magnetic field and chemical reaction. The crux of the analysis centres round, time-varying magnetic field, squeezing of the channel, chemical reaction of diffusing species and radiative heat transfer. These phenomena affect momentum, thermal energy and solutal transport mechanism significantly. The modified governing equations with complex boundary conditions contribute to intricacy of the solution. The Runge-Kutta sixth order integration scheme with shooting technique has been applied to solve the ordinary differential equations under similarity transformations. The analysis reveals that the numerical method applied in the present analysis is as effective and consistent as that of Homotopy Analysis Method (HAM). Further, it is interesting to note that the squeezing of the channel width acts adversely to the resistive force due to the presence of a magnetic field and hence suggests a controlling device to nullify the effect.

scholarly journals Effects of variable viscosity and thermal conductivity on unsteady MHD flow of non-Newtonian fluid over a stretching porous sheet

2013 ◽  
Vol 17 (4) ◽  
pp. 1035-1047 ◽  
Author(s):  
Abdel-Gamal Rahman
Keyword(s):  
Magnetic Field ◽  
Heat Transfer ◽  
Thermal Conductivity ◽  
Porous Medium ◽  
Differential Equations ◽  
Newtonian Fluid ◽  
Variable Viscosity ◽  
Mhd Flow ◽  
Transverse Magnetic ◽  
Electrically Conducting

The unsteady flow and heat transfer in an incompressible laminar, electrically conducting and non-Newtonian fluid over a non-isothermal stretching sheet with the variation in the viscosity and thermal conductivity in a porous medium by the influence of an external transverse magnetic field have been obtained and studied numerically. By using similarity analysis the governing differential equations are transformed into a set of non-linear coupled ordinary differential equations which are solved numerically. Numerical results were presented for velocity and temperature profiles for different parameters of the problem as power law parameter, unsteadiness parameter, radiation parameter, magnetic field parameter, porous medium parameter, temperature buoyancy parameter, Prandtl parameter, modified Eckert parameter, Joule heating parameter , heat source/sink parameter and others. A comparison with previously published work has been carried out and the results are found to be in good agreement. Also the effects of the pertinent parameters on the skin friction and the rate of heat transfer are obtained and discussed numerically and illustrated graphically.

The effect of radiation on free convective flow and mass transfer past a vertical isothermal cone surface with chemical reaction in the presence of a transverse magnetic field

2004 ◽  
Vol 82 (6) ◽  
pp. 447-458 ◽  
Author(s):  
A A Afify
Keyword(s):  
Magnetic Field ◽  
Mass Transfer ◽  
Boundary Conditions ◽  
Chemical Reaction ◽  
Transverse Magnetic Field ◽  
Convective Flow ◽  
Transverse Magnetic ◽  
Skin Friction Coefficient ◽  
Free Convective Flow ◽  
Cone Surface

The effects of radiation and chemical reactions, in the presence of a transverse magnetic field, on free convective flow and mass transfer of an optically dense viscous, incompressible, and electrically conducting fluid past a vertical isothermal cone surface are investigated. The nonlinear boundary-layer equations with the boundary conditions are transferred by a similarity transformation into a system of nonlinear ordinary differential equations with the appropriate boundary conditions. Furthermore, the similarity equations are solved numerically by using a fourth-order Runge–Kutta scheme with the shooting method. Numerical results for the skin-friction coefficient, the local Nusselt number, the local Sherwood number are given; as well, the velocity, temperature, and concentration profiles are presented for a Prandtl number of 0.7, the chemical-reaction parameter, the order of the reaction, the radiation parameter, the Schmidt number, the magnetic parameter, and the surface temperature parameter. PACS No.: 47.70.Fw

Gas-ionizing shocks in a magnetic field

1967 ◽  
Vol 1 (1) ◽  
pp. 37-54 ◽  
Author(s):  
M. D. Cowley
Keyword(s):  
Magnetic Field ◽  
Electric Field ◽  
Wave Speed ◽  
Normal Velocity ◽  
Electrically Conducting ◽  
Shock Stability ◽  
The Face ◽  
Arbitrary Velocity ◽  
Flow Plane ◽  
The Magnetic Field

Ionizing shocks for plane flows with the magnetic field lying in the flow plane are considered. The gas is assumed to be electrically conducting downstream, but non-conducting upstream. Shocks whose downstream state has a normal velocity component less than the slow magneto-acoustic-wave speed and whose upstream state is supersonic are found to be non-evolutionary in the face of plane magneto-acoustic disturbances, unless the upstream electric field in a frame of reference where the gas is at rest is arbitrary. Velocity conditions are also determined for shock stability with the electric field not arbitrary.Shock structures are found for the case of large ohmic diffusion, the initial temperature rise and ionization of the gas being caused by a thin transition having the properties of an ordinary gasdynamic shock. For the case where shocks are evolutionary when the upstream electric field is arbitrary, the shock structure requirements only restrict the electric field by limiting the range of possible values. When shocks are evolutionary with the electric field not arbitrary, they can only have a structure for a particular value of the electric field. Limits to the current carried by ionizing shocks and the effects of precursor ionization are discussed qualitatively.

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