MAGNETIC FIELD AND HEAT TRANSFER ANALYSIS OF HALBACH MAGNET ARRAYS FOR USE IN MAGNETIC REFRIGERATION SYSTEMS

2018 ◽  
Author(s):  
Erim Yanik ◽  
Abdullatif Hamad ◽  
Serdar Celik
Keyword(s):  
Magnetic Field ◽  
Heat Transfer ◽  
Magnetic Refrigeration ◽  
Heat Transfer Analysis

Conjugate Heat Transfer Analysis of Circular Microtube Under Time Varying Heat Source

2005 ◽  
Author(s):  
Abdullatif A. Gari ◽  
Muhammad M. Rahman
Keyword(s):  
Magnetic Field ◽  
Heat Transfer ◽  
Magnetic Material ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Transient Heat Conduction ◽  
Heat Transfer Analysis ◽  
Working Fluid ◽  
Heating And Cooling ◽  
The Magnetic Field

When a magnetic field is applied to a magnetic material it releases energy. It has been proven experimentally that this temperature rise could be as high as 20 K when a magnetic field of 10 T is applied. Heat is generated when the magnetic field is applied and cooling is produced when the magnetic field is released. The purpose of this study is to explore transient heat transfer coefficient when a fluid is circulated in the substrate through microchannels. Equations for the conservation of mass, momentum, and energy were solved in the fluid region. In the solid region, the transient heat conduction equation was solved. Gadolinium and water were picked as the magnetic material and working fluid respectively. The results are represented by plotting the variations of heat transfer coefficient and Nusselt number with time at various sections of the tube. The effects of the magnetic field strength, diameter of the microtube in the substrate, and Reynolds number were studied. It was found that the heat transfer coefficient changes with time in a periodic fashion when heating and cooling are generated in the system by repeated introduction and relaxation of the magnetic field. The results of this study will be useful for the development of microtube heat exchangers for a compact magnetic refrigerator.

scholarly journals A Note on the Unsteady Incompressible MHD Fluid Flow with Slip Conditions and Porous Walls

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
H. Zaman ◽  
Z. Ahmad ◽  
M. Ayub
Keyword(s):  
Magnetic Field ◽  
Heat Transfer ◽  
Heat Transfer Analysis ◽  
Slip Parameter ◽  
Slip Conditions ◽  
Flow And Heat Transfer ◽  
Transient Velocity ◽  
Suction Or Injection ◽  
Incompressible Mhd ◽  
The Magnetic Field

This work is concerned with the influence of uniform suction or injection on flow and heat transfer analysis of unsteady incompressible magnetohydrodynamic (MHD) fluid with slip conditions. The resulting unsteady problem for velocity and heat transfer is solved by means of Laplace transform. The characteristics of the transient velocity, overall transient velocity, steady state velocity and heat transfer at the walls are analyzed and discussed. Graphical results reveal that the magnetic field, slip parameter, and suction (injection) have significant influences on the velocity, and temperature distributions, which also changes the heat transfer behaviors at the two plates. The results of Fang (2004) are also recovered by keeping magnetic field and slip parameter absent.

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