scholarly journals Effect of Magnetic Field on Unsteady Flow of second order Oldroyd Visco-Elastic Liquid between Two Parallel Oscillating Flat Plates

2014 ◽  
Vol 10 (2) ◽  
pp. 53-56
Author(s):  
Anil Tripathi ◽  
◽  
A. K. Sharma ◽  
K.K. Singh
2021 ◽  
Vol 7 (5) ◽  
pp. 60
Author(s):  
Luis M. Moreno-Ramírez ◽  
Victorino Franco

The applicability of magnetocaloric materials is limited by irreversibility. In this work, we evaluate the reversible magnetocaloric response associated with magnetoelastic transitions in the framework of the Bean-Rodbell model. This model allows the description of both second- and first-order magnetoelastic transitions by the modification of the η parameter (η<1 for second-order and η>1 for first-order ones). The response is quantified via the Temperature-averaged Entropy Change (TEC), which has been shown to be an easy and effective figure of merit for magnetocaloric materials. A strong magnetic field dependence of TEC is found for first-order transitions, having a significant increase when the magnetic field is large enough to overcome the thermal hysteresis of the material observed at zero field. This field value, as well as the magnetic field evolution of the transition temperature, strongly depend on the atomic magnetic moment of the material. For a moderate magnetic field change of 2 T, first-order transitions with η≈1.3−1.8 have better TEC than those corresponding to stronger first-order transitions and even second-order ones.


1970 ◽  
Vol 25 (5) ◽  
pp. 608-611
Author(s):  
P. Zimmermann

Observing the change of the Hanle effect under the influence of a homogeneous electric field E the Stark effect of the (5p1/25d5/2)j=2-state in Sn I was studied. Due to the tensorial part β Jz2E2 in the Hamiltonian of the second order Stark effect the signal of the zero field crossing (M ∓ 2, M′ = 0 β ≷ 0 ) is shifted to the magnetic field H with gJμBH=2 | β | E2. From these shifts for different electric field strengths the value of the Stark parameter|β| = 0.21(2) MHz/(kV/cm)2 · gJ/1.13was deduced. A theoretical value of ß using Coulomb wave functions is discussed.


2016 ◽  
Vol 138 (12) ◽  
Author(s):  
M. M. Rahman

In this paper, we investigate the effects of second-order slip and magnetic field on the nonlinear mixed convection stagnation-point flow toward a vertical permeable stretching/shrinking sheet in an upper convected Maxwell (UCM) fluid with variable surface temperature. Numerical results are obtained using the bvp4c function from matlab for the reduced skin-friction coefficient, the rate of heat transfer, the velocity, and the temperature profiles. The results indicate that multiple (dual) solutions exist for a buoyancy opposing flow for certain values of the parameter space irrespective to the types of surfaces whether it is stretched or shrinked. It is found that an applied magnetic field compensates the suction velocity for the existence of the dual solutions. Depending on the parametric conditions; elastic parameter, magnetic field parameter, first- and second-order slip parameters significantly controls the flow and heat transfer characteristics. The illustrated streamlines show that for upper branch solutions, the effects of stretching and suction are direct and obvious as the flow near the surface is seen to suck through the permeable sheet and drag away from the origin of the sheet. However, aligned but reverse flow occurs for the case of lower branch solutions when the mixed convection effect is less significant.


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