Fully developed magnetohydrodynamics natural convection flow in a vertical micro-porous-channel with Hall effects

The effects of relative motion of magnetic field on unsteady magnetohydrodynamic free convection flow with ramped motion and temperature-dependent heat source/sink have been analyzed. The motion of the inner cylinder is ramped while the motion of the outer cylinder is fixed. The momentum and energy equations are solved using the well-known Laplace transform. The time-domain solution is obtained using the Riemann-sum approximation method. The influence of the governing parameters on fluid velocity, fluid temperature, volume flow rate, and rate of heat transfer are discussed with the help of line graphs. It is found that Hartmann number has a retarding effect on fluid velocity, skin friction at the outer surface of the inner cylinder, and mass flow rate when the magnetic field is fixed with the fluid and when the velocity of the magnetic field is less than the velocity of the moving cylinder. Whereas, the reverse effect is noticed when the magnetic field is fixed with the moving cylinder.

“…The set of Bessel ordinary differential equations (12) and (13) with the boundary condition (14) are solved for velocity and temperature in the Laplace domain as follows:…”

Section: Solutionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Influence of relative motion of magnetic field on time‐dependent MHD natural convection flow

Lawal

Jibril

2020

Section: Introductionmentioning

confidence: 99%

“…It was noted that irrespective of the thermal surrounding situation of the microporous channels, higher values of suction/ injection parameter improve shear stress at the boundary walls. In related work, Jha et al 37 investigated the impact of suction/injection on MHD flow in the existence of Hall current. Other notable works on this subject could be found in Krishna, 38 Jha and Aina, 39 and Singh et al 40 The present work is focused on investigating the interplay of suction and injection on the transient hydromagnetic flow of Newtonian viscous fluid through a microchannel in the prevalence of ion slip with Hall current and IMF effects.…”

Section: Introductionmentioning

confidence: 99%

Computational analysis and heat transfer on MHD transient‐free convection flow in a vertical microporous channel in the existence of Hall and ion slip current

Jha

Malgwi

2022

This investigation presents an analysis of the transient magnetohydrodynamic flow of Newtonian viscous fluid in a vertical microporous channel with the inclusion of ion slip‐Hall current as well as an induced magnetic field (IMF) effects. Owing to the nature of the flow equations which are difficult to obtain an analytical result, a numerical scheme (PDEPE) based on finite difference approximation is adopted in solving the governing dimensional partial differential equation. The active influence of different flow parameters on velocity and IMF along the main flow and induced flow directions are visualized. Furthermore, variations of shear stress and induced current density are also presented in tabular form for active nondimensional flow quantities and later on analyzed. To establish the validity of the results obtained in this computation, values for velocity and IMF in this analysis were correlated with the steady‐state existing benchmark when the values of nondimensional time are considered large. Significant results from the analysis show that at the transient time and in the simultaneous occurrence of suction/injection at the microchannel walls, higher values of ion slip current have no considerable influence on flow formation along the primary flow direction, whereas an oscillatory phenomenon is observed along the secondary flow direction. It is also significant to note that at a transient time, magnetic induction could be improved or controlled by choosing favorable values of the suction/injection parameter.

“…Hichem and Mahfoud 22 investigated the natural convection in a horizontal elliptical annulus containing a fluid saturated porous medium effect of aiding buoyancy for a low Rayleigh‐Darcy number. The MHD natural convection of nanofluid in a concentric annulus between a cold outer square cylinder and a heated inner circular was investigated by Sheikholeslami et al 23 Jha et al 24 considered the fully developed MHD natural convection flow in a vertical micro‐channel with the effect of a transverse magnetic field in the presence of velocity slip and temperature jump at the annular micro‐channel; they concluded that increase in curvature radius leads to an increase in the mass flow rate. In all the above mentioned works, flow formation is due to impulsive/accelerated motion of the cylinder.…”

Section: Introductionmentioning

confidence: 99%

Impact of relative motion of a magnetic field on unsteady magnetohydrodynamic natural convection flow with a constant heat source/sink

Lawal

Jibril

2020

This study analyzes time-dependent magnetohydrodynamics natural convective flow of a viscous incompressible fluid in an annulus with ramped motion of the boundaries. The governing momentum and energy equations are solved analytically, in terms of the modified Bessel function of the first and second kinds. The influence of governing parameters such as the Hartman number, radius ratio, Grashof number, heat absorption parameter, and Prandtl number are discussed with the help of line graphs. It is found that the Hartmann number has a retarding effect on fluid velocity when K = 0.0 and K = 0.5, while the reverse effect is noticed when K = 1.0. The Hartman number also decreases the mass flow rate for all cases of K while it enhances the skin friction at the inner surface of the outer cylinder. It increases the skin friction at the outer surface of the inner cylinder when K = 1.0 and K = 0.0, but decreases the skin friction at the outer surface of the inner cylinder when K = 0.5.