scholarly journals Numerical analysis of the onset of longitudinal convective rolls in a porous medium saturated by an electrically conducting nanofluid in the presence of an external magnetic field

2017 ◽  
Vol 7 ◽  
pp. 2134-2152 ◽  
Author(s):  
Abderrahim Wakif ◽  
Zoubair Boulahia ◽  
Rachid Sehaqui
Keyword(s):  
Magnetic Field ◽  
Porous Medium ◽  
Numerical Analysis ◽  
External Magnetic Field ◽  
Electrically Conducting ◽  
Convective Rolls

scholarly journals Span-Wise Fluctuating MHD Convective Flow of a Viscoelastic Fluid through a Porous Medium in a Hot Vertical Channel with Thermal Radiation

2016 ◽  
Vol 21 (3) ◽  
pp. 667-681 ◽  
Author(s):  
K.D. Singh
Keyword(s):  
Magnetic Field ◽  
Porous Medium ◽  
Vertical Channel ◽  
Magnetic Reynolds Number ◽  
Conducting Fluid ◽  
Temperature Fields ◽  
Convection Flow ◽  
Electrically Conducting ◽  
Unsteady Mixed Convection ◽  
Phase Angles

Abstract An unsteady mixed convection flow of a visco-elastic, incompressible and electrically conducting fluid in a hot vertical channel is analyzed. The vertical channel is filled with a porous medium. The temperature of one of the channel plates is considered to be fluctuating span-wise cosinusoidally, i.e., $T^* \left( {y^* ,z^* ,t^* } \right) = T_1 + \left( {T_2} - {T_ 1} \right)\cos \left( {{{\pi z^* } \over d} - \omega ^* t^* } \right)$ . A magnetic field of uniform strength is applied perpendicular to the planes of the plates. The magnetic Reynolds number is assumed very small so that the induced magnetic field is neglected. It is also assumed that the conducting fluid is gray, absorbing/emitting radiation and non-scattering. Governing equations are solved exactly for the velocity and the temperature fields. The effects of various flow parameters on the velocity, temperature and the skin friction and the Nusselt number in terms of their amplitudes and phase angles are discussed with the help of figures.

scholarly journals Soret effects due to natural convection in a non-Newtonian fluid flow in porous medium with heat and mass transfer

2014 ◽  
Vol 11 (2) ◽  
pp. 147-156 ◽  
Author(s):  
M.C Raju ◽  
S.V.K Varma
Keyword(s):  
Magnetic Field ◽  
Porous Medium ◽  
Fluid Flow ◽  
Newtonian Fluid ◽  
Porous Plate ◽  
Sink Strength ◽  
Suction Parameter ◽  
Electrically Conducting ◽  
Highly Nonlinear ◽  
Constant Suction

The problem of unsteady MHD free convective, incompressible electrically conducting, non-Newtonian fluid through porous medium bounded by an infinite porous plate in the presence of constant suction has been studied. A magnetic field of uniform strength is assumed to be applied normal to the plate. The equations governing the fluid flow which are highly nonlinear are reduced to linear by using perturbation method and have been solved subject to the relevant boundary conditions. It is noted that the velocity of the fluid is increased as Soret number and suction parameter increase, whereas reverse phenomenon is observed in case of magnetic field strength and sink strength. DOI: http://dx.doi.org/10.3329/jname.v11i2.17563

Combined Effect of Temperature Modulation and Magnetic Field on the Onset of Convection in an Electrically Conducting-Fluid-Saturated Porous Medium

2008 ◽  
Vol 130 (5) ◽  
Author(s):  
B. S. Bhadauria
Keyword(s):  
Magnetic Field ◽  
Porous Medium ◽  
Saturated Porous Medium ◽  
Effect Of Temperature ◽  
Temperature Modulation ◽  
Vertical Magnetic Field ◽  
Onset Of Convection ◽  
Electrically Conducting ◽  
Electrically Conducting Fluid ◽  
Fluid Saturated Porous Medium

The effect of temperature modulation on the onset of thermal convection in an electrically conducting fluid-saturated-porous medium, heated from below, has been studied using linear stability analysis. The amplitudes of temperature modulation at the lower and upper surfaces are considered to be very small. The porous medium is confined between two horizontal walls and subjected to a vertical magnetic field; flow in porous medium is characterized by Brinkman–Darcy model. Considering only infinitesimal disturbances, and using perturbation procedure, the combined effect of temperature modulation and vertical magnetic field on thermal instability has been studied. The correction in the critical Rayleigh number is calculated as a function of frequency of modulation, Darcy number, Darcy Chandrasekhar number, magnetic Prandtl number, and the nondimensional group number χ. The influence of the magnetic field is found to be stabilizing. Furthermore, it is also found that the onset of convection can be advanced or delayed by proper tuning of the frequency of modulation. The results of the present model have been compared with that of Darcy model.

Gravity flow of pulsatile blood through a porous medium under periodic body acceleration and magnetic field in an inclined tube

2016 ◽  
Vol 09 (02) ◽  
pp. 1650025 ◽  
Author(s):  
Shakera Tanveer ◽  
V. P. Rathod
Keyword(s):  
Magnetic Field ◽  
Mathematical Model ◽  
Porous Medium ◽  
Couple Stress ◽  
Gravity Flow ◽  
Body Acceleration ◽  
Electrically Conducting ◽  
Engineering Sciences ◽  
Velocity Flow ◽  
Inclined Tube

Mathematical model for the pulsatile blood flow through a porous medium under the influence of periodic body acceleration for gravity flow along an inclined tube by considering blood as a couple stress, incompressible and electrically conducting fluid in the presence of magnetic field has been investigated. Analytical expressions for axial velocity, flow rate, fluid acceleration and shear stress are obtained by applying the Laplace and finite Hankel’s transforms. The velocity profiles for various values of Hartmann number, couple stress parameters and the angle of inclination are shown graphically. Also the effects of body acceleration, Womerseley parameters and permeability parameters have been discussed. The results obtained in the present mathematical model for different values of the parameters involved in the problem show that the flow of blood is influenced by the effect of magnetic field, the porous medium and the inclination angle. The present model is compared with the other existing models. Through this theoretical investigation, the applications of magnetic field have also been indicated in the field of biological, biomedical and engineering sciences.

The Thermoelectric-Hydromagnetic Pump

1964 ◽  
Vol 86 (2) ◽  
pp. 166-168 ◽  
Author(s):  
J. F. Osterle ◽  
S. W. Angrist
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Magnetic Flux ◽  
Flux Density ◽  
Pressure Rise ◽  
Maximum Efficiency ◽  
Magnetic Flux Density ◽  
Optimum Thickness ◽  
Pumping Power ◽  
Electrically Conducting

A thermally powered pump for fluids which are electrically conducting, which utilizes the Lorentz force between an electric current induced by the Seebeck effect, and an external magnetic field is examined. The pressure rise in the pump is found to be proportional to the magnetic flux density while the flow rate is found to be inversely proportional to the magnetic flux density. Thus the pumping power and efficiency (both being proportional to the product of pressure rise and flow) are independent of the applied magnetic field. Calculations for a pump with constantan walls handling sodium and utilizing a temperature difference of 300 deg C show that a maximum efficiency of close to seven-tenths of a percent is possible. If the same pump is constructed with optimum thickness walls made of the semiconductor AgSbTe2, it would have an efficiency of nearly six percent.

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