scholarly journals Study of Blood Flow with Effects of Slip in Arterial Stenosis Due to Presence of Transverse Magnetic Field

2013 ◽  
Vol 4 (2) ◽  
pp. 215-226
Author(s):  
Sarfraz Ahmed
Keyword(s):  
Magnetic Field ◽  
Reynolds Number ◽  
Blood Flow ◽  
Transverse Magnetic Field ◽  
Hartmann Number ◽  
Fluid Velocity ◽  
Equations Of Motion ◽  
Circulatory System ◽  
Transverse Magnetic ◽  
Arterial Stenosis

The flow of blood in human circulatory system can be controlled by applying appropriate magnetic field. It is also well known that non-Newtonian nature of blood significantly influences the flows, particularly in the cases where blood vessels are curved, branching or narrow etc. Stenosis refers to localized narrowing of an artery and is a frequent result of arterial disease and is caused mainly due to intravascular atherosclerotic plaque which develops at the arterial wall and protrudes into the lumen of the vessel. Such constrictions disturb normal blood flow through the artery. Here study is made on the flow of blood through a stenosed artery with the effect of slip at the boundary in presence of transverse magnetic field considering blood as Casson fluid (non- Newtonian fluid). The equations of motion has have been solved numerically. The effect of various parameters on the flow characteristics like Hartmann number, Reynolds number has been discussed. Numerical results were obtained for different values of the Hartmann number M and Reynolds number Re. It is observed that the fluid velocity decreases as the Hartmann number increases.

Numerical study of magnetohydrodynamics Jeffery–Hamel flow with cu-water nanofluid between two rectangular smooth walls with transverse magnetic field

2020 ◽  
Vol 09 (02) ◽  
pp. 2050010
Author(s):  
Ramakanta Meher ◽  
N. D. Patel
Keyword(s):  
Magnetic Field ◽  
Reynolds Number ◽  
Velocity Profile ◽  
Transverse Magnetic Field ◽  
Hartmann Number ◽  
Numerical Study ◽  
Transverse Magnetic ◽  
Differential Transform Method ◽  
Transform Method ◽  
Differential Transform

In this paper, the MHD Jeffery–Hamel flow with cu-water nanofluid between two smooth rectangular walls with the transverse magnetic field is studied. Differential transform method (DTM) is used to obtain the velocity profile of Jeffery–Hamel flow in both convergent and divergent channels for different values of Reynolds number and Hartmann number. Finally, to examine the accuracy and the validity of the method, the obtained results have been compared with the available collation method results.

scholarly journals Influence of Magnetic Field on the Peristaltic Flow of a Viscous Fluid through a Finite-Length Cylindrical Tube

2010 ◽  
Vol 7 (3) ◽  
pp. 169-176 ◽  
Author(s):  
S. K. Pandey ◽  
Dharmendra Tripathi
Keyword(s):  
Magnetic Field ◽  
Viscous Fluid ◽  
Transverse Magnetic Field ◽  
Finite Length ◽  
Flow Rate ◽  
Hartmann Number ◽  
Volume Flow Rate ◽  
Critical Value ◽  
Transverse Magnetic ◽  
Volume Flow

The paper presents an analytical investigation of the peristaltic transport of a viscous fluid under the influence of a magnetic field through a tube of finite length in a dimensionless form. The expressions of pressure gradient, volume flow rate, average volume flow rate and local wall shear stress have been obtained. The effects of the transverse magnetic field and electrical conductivity (i.e. the Hartmann number) on the mechanical efficiency of a peristaltic pump have also been studied. The reflux phenomenon is also investigated. It is concluded, on the basis of the pressure distribution along the tubular length and pumping efficiency, that if the transverse magnetic field and the electric conductivity increase, the pumping machinery exerts more pressure for pushing the fluid forward. There is a linear relation between the averaged flow rate and the pressure applied across one wavelength that can restrain the flow due to peristalsis. It is found that there is a particular value of the averaged flow rate corresponding to a particular pressure that does not depend on the Hartmann number. Naming these values ‘critical values’, it is concluded that the pressure required for checking the flow increases with the Hartmann number above the critical value and decreases with it below the critical value. It is also inferred that magneto-hydrodynamic parameters make the fluid more prone to flow reversal. The conclusion applied to oesophageal swallowing reveals that normal water is easier to swallow than saline water. The latter is more prone to flow reversal. A significant difference between the propagation of the integral and non-integral number of waves along the tube is that pressure peaks are identical in the former and different in the latter cases.

Analytical Analysis of Magneto-hydrodynamic (MHD) Transient Flow Past a Suddenly Started Infinite Vertical Plate With Thermal Radiation and Ramped Wall Temperature

2014 ◽  
Vol 136 (4) ◽  
Author(s):  
N. Ahmed ◽  
M. Dutta
Keyword(s):  
Magnetic Field ◽  
Heat Transfer ◽  
Reynolds Number ◽  
Transverse Magnetic Field ◽  
Wall Temperature ◽  
Vertical Plate ◽  
Transverse Magnetic ◽  
Viscous Drag ◽  
Fluid Temperature ◽  
Infinite Vertical Plate

An exact solution to the problem of a magnetohydrodynamic viscous, incompressible free convective flow of an electrically conducting, Newtonian non-Gray fluid past a suddenly started infinite vertical plate with ramped wall temperature in presence of appreciable radiation heat transfer and uniform transverse magnetic field is presented. The fluid is assumed to be optically thin and the magnetic Reynolds number is considered small enough to neglect the induced hydromagnetic effects. The resulting system of the equations governing the flow is solved by adopting Laplace Transform technique in closed form. Detailed computations of the influence of Hartmann number, radiation conduction parameter Q, Reynolds number Re and time t on the variations in the fluid velocity, fluid temperature, and skin friction and Nusselt number at the plate are demonstrated graphically. The results show that the imposition of the transverse magnetic field retards the fluid motion and causes the viscous drag at the plate to fall. The investigation simulates that the fluid temperature drops and the rate of heat transfer from the plate to the fluid gets increased for increasing Reynolds number.

Wake structure of laminar flow past a sphere under the influence of a transverse magnetic field

2019 ◽  
Vol 873 ◽  
pp. 151-173
Author(s):  
Jun-Hua Pan ◽  
Nian-Mei Zhang ◽  
Ming-Jiu Ni
Keyword(s):  
Magnetic Field ◽  
Reynolds Number ◽  
Magnetic Fields ◽  
Transverse Magnetic Field ◽  
Symmetry Plane ◽  
Transverse Magnetic ◽  
Symmetric State ◽  
Wake Structure ◽  
Plane Symmetric ◽  
Double Plane

The wake structure of an incompressible, conducting, viscous fluid past an electrically insulating sphere affected by a transverse magnetic field is investigated numerically over flow regimes including steady and unsteady laminar flows at Reynolds numbers up to 300. For a steady axisymmetric flow affected by a transverse magnetic field, the wake structure is deemed to be a double plane symmetric state. For a periodic flow, unsteady vortex shedding is first suppressed and transitions to a steady plane symmetric state and then to a double plane symmetric pattern. Wake structures in the range $210<Re\leqslant 300$ without a magnetic field have a symmetry plane. An angle $\unicode[STIX]{x1D703}$ exists between the orientation of this symmetry plane and the imposed transverse magnetic field. For a given transverse magnetic field, the final wake structure is found to be independent of the initial flow configuration with a different angle $\unicode[STIX]{x1D703}$. However, the orientation of the symmetry plane tends to be perpendicular to the magnetic field, which implies that the transverse magnetic field can control the orientation of the wake structure of a free-moving sphere and change the direction of its horizontal motion by a field–wake–trajectory control mechanism. An interesting ‘reversion phenomenon’ is found, where the wake structure of the sphere at a higher Reynolds number and a certain magnetic interaction parameter ($N$) corresponds to a lower Reynolds number with a lower $N$ value. Furthermore, the drag coefficient is proportional to $N^{2/3}$ for weak magnetic fields or to $N^{1/2}$ for strong magnetic fields, where the threshold value between these two regimes is approximately $N=4$.

Control of Vortex Shedding From a Bluff Body Using Imposed Magnetic Field

2006 ◽  
Vol 129 (5) ◽  
pp. 517-523 ◽  
Author(s):  
Sintu Singha ◽  
K. P. Sinhamahapatra ◽  
S. K. Mukherjea
Keyword(s):  
Magnetic Field ◽  
Reynolds Number ◽  
Steady Flow ◽  
Transverse Magnetic Field ◽  
Vortex Shedding ◽  
Bluff Body ◽  
Reynolds Numbers ◽  
Transverse Magnetic ◽  
Staggered Grid ◽  
The Magnetic Field

The two-dimensional incompressible laminar viscous flow of a conducting fluid past a square cylinder placed centrally in a channel subjected to an imposed transverse magnetic field has been simulated to study the effect of a magnetic field on vortex shedding from a bluff body at different Reynolds numbers varying from 50 to 250. The present staggered grid finite difference simulation shows that for a steady flow the separated zone behind the cylinder is reduced as the magnetic field strength is increased. For flows in the periodic vortex shedding and unsteady wake regime an imposed transverse magnetic field is found to have a considerable effect on the flow characteristics with marginal increase in Strouhal number and a marked drop in the unsteady lift amplitude indicating a reduction in the strength of the shed vortices. It has further been observed, that it is possible to completely eliminate the periodic vortex shedding at the higher Reynolds numbers and to establish a steady flow if a sufficiently strong magnetic field is imposed. The necessary strength of the magnetic field, however, depends on the flow Reynolds number and increases with the increase in Reynolds number. This paper describes the algorithm in detail and presents important results that show the effect of the magnetic field on the separated wake and on the periodic vortex shedding process.

Magnetohydrodynamic channel flows with weak transverse magnetic fields

2014 ◽  
Vol 372 (2020) ◽  
pp. 20130344
Author(s):  
A. P. Rothmayer
Keyword(s):  
Magnetic Field ◽  
Reynolds Number ◽  
High Reynolds Number ◽  
Hartmann Number ◽  
Plane Channel ◽  
Transverse Magnetic ◽  
Unsteady Viscous Flow ◽  
High Reynolds ◽  
Magnetohydrodynamic Channel ◽  
The Magnetic Field

Magnetohydrodynamic flow of an incompressible fluid through a plane channel with slowly varying walls and a magnetic field applied transverse to the channel is investigated in the high Reynolds number limit. It is found that the magnetic field can first influence the hydrodynamic flow when the Hartmann number reaches a sufficiently large value. The magnetic field is found to suppress the steady and unsteady viscous flow near the channel walls unless the wall shapes become large.

scholarly journals CONVECTIVE HEAT TRANSFER ON STENOSED BLOOD FLOW THROUGH PERMEABLE MICROCIRCULATION IN THE PRESENCE OF A MAGNETIC FIELD

2020 ◽  
Author(s):  
Alana Sankar ◽  
Sreedhara Rao Gunakala ◽  
Donna Comissiong
Keyword(s):  
Magnetic Field ◽  
Heat Transfer ◽  
Reynolds Number ◽  
Blood Flow ◽  
Nusselt Number ◽  
Convective Heat Transfer ◽  
Convective Heat ◽  
Hartmann Number ◽  
Darcy Number ◽  
Flow Through

Blood flow through permeable microcirculation in the presence of a composite stenosis, an external magnetic field and convective heat transfer was examined. A two-layered model for the blood consisting of a fluid-particle suspension in the core region with a peripheral cell-free plasma layer was used. The proposed system of equations was solved and plots were generated. In the presence of permeable walls, an external magnetic field and convective heat transfer, the temperature of the blood, friction-factor Reynolds number and Nusselt number were investigated. The temperature of the blood increased when the Hartmann number increased, Darcy number increased, haematocrit level increased or the peripheral layer thinned. The friction-factor Reynolds number product increased as the haematocrit, Hartmann number, stenosis height or Darcy number increased. The Nusselt number decreased as the Hartmann number, haematocrit, stenosis height or Darcy number increased. These results were interpreted in terms of the physical situation. This study aids in understanding the effects of wall permeability, a magnetic field and the presence of heat transfer on different diseased arterial systems in the future.

scholarly journals Free convective flow of a couple stress fluid through a vertical porous channel in the presence of a transverse magnetic field

2018 ◽  
Vol 12 (1) ◽  
pp. 49-62
Author(s):  
M. Prasad Siddalinga ◽  
B. S. Shashikala
Keyword(s):  
Magnetic Field ◽  
Transverse Magnetic Field ◽  
Couple Stress ◽  
Hartmann Number ◽  
Transverse Magnetic ◽  
Porous Channel ◽  
Couple Stress Fluid ◽  
Physical Parameters ◽  
Stress Parameter ◽  
Buoyancy Parameter

Nonlinear oberbeck convection of a couple stress fluid in a vertical porous channel in the presence of transverse magnetic field is investigated in this paper. Analytical solution is obtained using the perturbation technique for vanishing values of the buoyancy parameter. Numerical solution of the nonlinear governing equations is obtained using the finite difference technique to validate the results obtained from the analytical solutions. The influence of the physical parameters on the flow, such as couple stress parameter, Hartmann number, temperature parameter, porous parameter and buoyancy parameter are evaluated and presented graphically. A new approach is used to analyse the flow for strong, weak and comparable porosity cases. It is found that increase in porous parameter, couple stress parameter, Hartmann number and temperature parameters decrease the velocity considerably.Kathmandu University Journal of Science, Engineering and Technology Vol. 12, No. I, June, 2016, Page: 49-62

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