Effect of induced magnetic field and linear / non-linear vertical stretching sheet on mixed convection Jeffrey fluid near a stagnation-point flow through a porous medium with suction or injection

An analysis is made of the steady laminar axisymmetric stagnation point flow of an incompressible viscous fluid in a porous medium impinging on a permeable radially stretching sheet with heat generation or absorption. A uniform suction or blowing is applied normal to the plate which is maintained at a constant temperature. Similarity transformation is used to transform the governing partial differential equations to ordinary differential equations. The finite difference method and generalized Thomas algorithm are used to solve the governing nonlinear momentum and energy equations. The effects of the uniform suction/blowing velocity, the stretching parameter and the heat generation/absorption coefficient on both the flow field and heat transfer are presented and discussed. The results indicate that increasing the stretching parameter or the suction/blowing velocity decreases both the velocity and thermal boundary layer thicknesses. The effect of the stretching parameter on the velocity components is more apparent for suction than blowing while its effect on the temperature and rate of heat transfer at the wall is clearer in the case of blowing than suction.

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MHD mixed convection boundary layer stagnation-point flow on a vertical surface with induced magnetic field

International Journal of Numerical Methods for Heat &amp Fluid Flow ◽

10.1108/hff-11-2016-0436 ◽

2019 ◽

Vol 30 (11) ◽

pp. 4697-4710 ◽

Cited By ~ 2

Author(s):

Fadzilah Md Ali ◽

Kohilavani Naganthran ◽

Roslinda Nazar ◽

Ioan Pop

Keyword(s):

Magnetic Field ◽

Boundary Layer ◽

Stability Analysis ◽

Mixed Convection ◽

Stagnation Point ◽

Stagnation Point Flow ◽

Convection Boundary Layer ◽

Induced Magnetic Field ◽

Content Type ◽

The Stability

Purpose This study aims to perform a stability analysis on a steady magnetohydrodynamic (MHD) mixed convection boundary-layer stagnation-point flow of an incompressible, viscous and electrically conducting fluid over a vertical flat plate. The effect of induced magnetic field is also considered. Design/methodology/approach The governing boundary layer equations are transformed into a system of ordinary differential equations using the similarity transformations. The system is then solved numerically using the “bvp4c” function in MATLAB. Findings Dual solutions are found to exist for a certain range of the buoyancy parameter for both the assisting and opposing flows. The results from the stability analysis showed that the first solution (upper branch) is stable and valid physically, while the second solution (lower branch) is unstable. Practical implications This problem is important in many metallurgical processes, namely, drawing, annealing and tinning of copper wires. The results obtained are very useful for researchers to determine which solution is physically stable, whereby mathematically more than one solution exists for the skin friction coefficient and the heat transfer characteristics. Originality/value The present results of the stability analysis are original and new for the problem of MHD mixed convection stagnation-point flow of viscous conducting fluid over a vertical flat plate, with the effect of induced magnetic field.

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