scholarly journals Stability analysis of magnetic fluids in the presence of an oblique field and mass and heat transfer

2020 ◽  
Vol 330 ◽  
pp. 01035
Author(s):  
Rabah Djeghiour ◽  
Bachir Meziani
Keyword(s):  
Magnetic Field ◽  
Heat Transfer ◽  
Magnetic Fluids ◽  
Physical Parameters ◽  
Stability Diagrams ◽  
Stability And Instability ◽  
Mass And Heat Transfer ◽  
Model Equations ◽  
The Stability ◽  
Oblique Magnetic Field

In this paper, we investigate an analysis of the stability of a basic flow of streaming magnetic fluids in the presence of an oblique magnetic field is made. We have use the linear analysis of modified Kelvin-Helmholtz instability by the addition of the influence of mass transfer and heat across the interface. Problems equations model is presented where nonlinear terms are neglected in model equations as well as the boundary conditions. In the case of a oblique magnetic field, the dispersion relation is obtained and discussed both analytically and numerically and the stability diagrams are also obtained. It is found that the effect of the field depends strongly on the choice of some physical parameters of the system. Regions of stability and instability are identified. It is found that the mass and heat transfer parameter has a destabilizing influence regardless of the mechanism of the field.

Nonlinear electrohydrodynamic Rayleigh–Taylor instability with mass and heat transfer: effect of a normal field

1994 ◽  
Vol 72 (9-10) ◽  
pp. 537-549 ◽  
Author(s):  
Abou El Magd A. Mohamed ◽  
Abdel Raouf F. Elhefnawy ◽  
Y. D. Mahmoud
Keyword(s):  
Heat Transfer ◽  
Multiple Scales ◽  
Landau Equation ◽  
Finite Thickness ◽  
Surface Charges ◽  
Stability Diagrams ◽  
Dielectric Fluids ◽  
Mass And Heat Transfer ◽  
The Stability ◽  
Cubic Nonlinear Schrödinger Equation

The nonlinear electrohydrodynamic stability of two superposed dielectric fluids with interfacial transfer of mass and heat is presented for layers of finite thickness. The fluids are subjected to a normal electric field in the absence of surface charges. Using a technique based on the method of multiple scales it is shown that the evolution of the amplitude is governed by a Ginzburg–Landau equation. When the mass and heat transfer are neglected, the cubic nonlinear Schrödinger equation is obtained. Further, it is shown that, near the marginal state, a nonlinear diffusion equation is obtained in the presence of mass and heat transfer. The various stability criteria are discussed both analytically and numerically and the stability diagrams are obtained.

Nonlinear Kelvin—Helmholtz instability in magnetic fluids of finite thickness: effects of a tangential magnetic field

1994 ◽  
Vol 51 (3) ◽  
pp. 451-465 ◽  
Author(s):  
Abdel Raouf F. Elhefnawy
Keyword(s):  
Magnetic Field ◽  
Multiple Scales ◽  
Second Harmonic ◽  
Wave Train ◽  
Finite Thickness ◽  
Magnetic Fluids ◽  
Two Dimensions ◽  
Stability And Instability ◽  
Regions Of Stability ◽  
The Stability

The nonlinear stability of a horizontal interface separating two streaming magnetic fluids of finite thickenss is investigated in two dimensions. The fluids are considered to be inviscid and incompressible. The magnetic field is applied along the direction of streaming. The method of multiple scales, in both space and time, is used to examine the stability properties of the system arising from second-harmonic resonance. A pair of partial differential equations for the amplitude of the wave and its second harmonic are derived. These describe the evolution of the wave train up to cubic order, and may be regarded as the counterparts of the single nonlinear Schrödinger equation that occurs in the non-resonant case. The stability condition of this equation is discussed both analytically and numerically, and stability diagrams are obtained. Regions of stability and instability are identified. The nonlinear cut-off wavenumber separating the regions of stability from those of instability is obtained. The equation governing the evolution of the amplitude at the critical point is also obtained, which leads to a nonlinear Klein—Gordon equation.

MHD and Stability for Convective Flow of Micropolar Nanofluid over a Moving and Vertical Permeable Plate

2021 ◽  
Vol 408 ◽  
pp. 51-65
Author(s):  
Reda Alouaoui ◽  
Samira Ferhat ◽  
M.N. Bouaziz
Keyword(s):  
Magnetic Field ◽  
Heat Transfer ◽  
Physical Parameters ◽  
Governing Equations ◽  
Permeable Plate ◽  
Micropolar Nanofluid ◽  
The Finite Difference Method ◽  
The Stability ◽  
The Magnetic Field ◽  
Suspended Nanoparticles

This work mainly studies the effect of the magnetic field, the suction /injection, the Brownian and thermphorese diffusions and the stability on heat transfer in a laminar boundary layer flux of micropolar nanofluids flow adjacent to moving vertical permeable plate. The appropriate governing equations developed are reduced by the transformation of similarity which are solved using the finite difference method that implements the 3-stage Lobatto collocation formula. A parametric study of the physical parameters is carried out to show their influence on the different profiles. The results show that the microrotation of the suspended nanoparticles and the presence of the magnetic field become important on the heat transfer with good chemical stability of the micropolar nanofluids.

scholarly journals Tuning of Heat Transfer Rate of Cobalt Manganese Ferrite Based Magnetic Fluids in Varying Magnetic Field

2017 ◽  
Vol 23 (3) ◽  
Author(s):  
Margabandhu MARIMUTHU ◽  
Sendhilnathan SECHASSALOM ◽  
Sirikanjana THONGMEE
Keyword(s):  
Magnetic Field ◽  
Heat Transfer ◽  
Heat Transfer Rate ◽  
Transfer Rate ◽  
Magnetic Fluids ◽  
Manganese Ferrite

Fluid flow analysis of cilia beating in a curved channel in the presence of magnetic field and heat transfer

2020 ◽  
Vol 98 (2) ◽  
pp. 191-197 ◽  
Author(s):  
Hina Sadaf ◽  
S. Nadeem
Keyword(s):  
Magnetic Field ◽  
Heat Transfer ◽  
Velocity Profile ◽  
Flow Analysis ◽  
Fluid Motion ◽  
Flow Characteristics ◽  
Physical Parameters ◽  
Curved Channel ◽  
Radial Magnetic Field ◽  
Fluid Flow Analysis

This paper investigates fluid motion generated by cilia and a pressure gradient in a curved channel. The flow analysis is carried out in the presence of heat transfer and radial magnetic field. The leading equations are simplified under the familiar suppositions of large wavelength and small Reynolds number approximations. An exact solution has been developed for the velocity profile. The flow characteristics of the viscous fluid are computed in the presence of cilia and metachronal wave velocity. The effects of several stimulating parameters on the flow and heat transfer are studied in detail through graphs. It is found that symmetry of the velocity profile is broken owing to bending of the channel. The radially varying magnetic field decreases the velocity field, but near the left ciliated wall it induces the opposite behavior. It is also found that velocity profile increases due to increase in buoyancy forces throughout the domain. Numerical consequences for velocity profile are also accessible in the table for diverse values of the physical parameters.

scholarly journals Effect of Velocity Slip Boundary Condition on the Flow and Heat Transfer of Cu-Water and TiO2-Water Nanofluids in the Presence of a Magnetic Field

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Abdelhalim Ebaid ◽  
Fahd Al Mutairi ◽  
S. M. Khaled
Keyword(s):  
Magnetic Field ◽  
Heat Transfer ◽  
Fluid Velocity ◽  
Velocity Slip ◽  
Slip Boundary Condition ◽  
Dual Solutions ◽  
Slip Condition ◽  
Shrinking Sheet ◽  
Physical Parameters ◽  
Flow And Heat Transfer

In nanofluid mechanics, it has been proven recently that the no slip condition at the boundary is no longer valid which is the reason that we consider the effect of such slip condition on the flow and heat transfer of two types of nanofluids. The present paper considers the effect of the velocity slip condition on the flow and heat transfer of the Cu-water and the TiO2-water nanofluids over stretching/shrinking sheets in the presence of a magnetic field. The exact expression for the fluid velocity is obtained in terms of the exponential function, while an effective analytical procedure is suggested and successfully applied to obtain the exact temperature in terms of the generalized incomplete gamma function. It is found in this paper that the Cu-water nanofluid is slower than the TiO2-water nanofluid for both cases of the stretching/shrinking sheets. However, the temperature of the Cu-water nanofluid is always higher than the temperature of the TiO2-water nanofluid. In the case of shrinking sheet the dual solutions have been obtained at particular values of the physical parameters. In addition, the effect of various physical parameters on such dual solutions is discussed through the graphs.

Influence of Heat Transfer and Magnetic Field on a Peristaltic Transport of a Jeffrey Fluid in an Asymmetric Channel with Partial Slip

2010 ◽  
Vol 65 (6-7) ◽  
pp. 483-494 ◽  
Author(s):  
Sohail Nadeem ◽  
Safia Akram
Keyword(s):  
Magnetic Field ◽  
Heat Transfer ◽  
Wave Length ◽  
Pressure Rise ◽  
Peristaltic Transport ◽  
Partial Slip ◽  
Jeffrey Fluid ◽  
Physical Parameters ◽  
Asymmetric Channel ◽  
Wave Forms

In the present paper, we have studied the influence of heat transfer and magnetic field on a peristaltic transport of a Jeffrey fluid in an asymmetric channel with partial slip. The complicated Jeffrey fluid equations are simplified using the long wave length and low Reynolds number assumptions. In the wave frame of reference, an exact and closed form of Adomian solution is presented. The expressions for pressure drop, pressure rise, stream function, and temperature field have been calculated. The behaviour of different physical parameters has been discussed graphically. The pumping and trapping phenomena of various wave forms (sinusoidal, multisinusoidal, square, triangular, and trapezoidal) are also studied.

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