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1

Effects of variable fluid properties and mixed convection on biomagnetic fluid flow and heat transfer over a stretching sheet in the presence of magnetic dipole

Murtaza M. G., Alam Jahangir, Tzirtzilakis E. E., Shamshuddin Md., Ferdows M.

Journal of Power Technologies

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2023

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Vol. 103, nr 4

193--208

EN

This investigations covers the numerical analysis of a steady biomagnetic fluid flow (BFD) that passed through a two dimensional stretching sheet under the influence of magnetic dipole. The effect of fluid variable viscosity and thermal conductivity are also taken into consideration as assumed to vary as linear function of temperature. Our model mathematically formulated for BFD namely blood which consist of principles of magnetohydrodynamic (MHD) and ferrohydrodynamic (FHD), where blood treated as an electrically conducting fluid as well as polarization. Using similarity transformations, the governing system of partial differential equations are transferred into system of ordinary differential equations (ODE). The resulting coupled non linear ODE is numerically solved by employing bvp4c function technique available in MATLAB software. The effects of pertinent parameters namely ferromagnetic interaction parameter, magnetic field parameter, mixed convection parameter, viscosity variation parameter, Prandtl number, thermal conductivity parameter etc are plotted and discussed adequately for velocity and temperature profile as well as skin friction coefficient and rate of heat transfer. The results revels that velocity profile decreases as enhanced values of ferromagnetic number whereas temperature profile increased. Also found that skin friction coefficient reduces and rate of heat transfer increases by increasing values of thermal conductivity parameter and viscosity variation parameter. For numerical validation a comparisons has been made for some specific values with previous investigators. We hope that the present analysis will present in bio-medical and bio-engineering sciences.

2

Magnetohydrodynamic flow around an elongated cylinder in non-Darcian porous regime with higher order chemical reaction and Soret/Dufour effects

Das Utpal Jyoti, Begum Jubi

International Journal of Applied Mechanics and Engineering

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2023

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Vol. 28, no. 1

11--22

EN

Here, we consider magnetohydrodynamic flow of an incompressible, time independent fluid past an elongated cylinder surrounded in a non-Darcian porous regime with magnetic flux supplied at an acute angle. The Soret/Dufour effects and the higher order chemical reactions are also included in the present study. The subsequent governing equations are resolved using the MATLAB-bvp4c method. The flow velocity appears to decrease with the growth of the Reynolds number, inertia parameter, magnetic field and angle of inclination of the magnetic flux, but improves with the Darcy number. The inertia parameter enhances the fluid temperature and skin friction. Further order of chemical reaction, Soret/ Dufour number plays a significant role in the system.

3

MHD forced convection using ferrofluid over a backward facing step containing a finned cylinder

Toumi Meriem, Bouzit Mohamed, Bouzit Fayçal, Mokhefi Abderrahim

Acta Mechanica et Automatica

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2022

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Vol. 16, no. 1

70--81

EN

In this paper, a numerical study of forced convection on a backward facing step containing a single-finned fixed cylinder has been performed, using a ferrofluid and external magnetic field with different inclinations. The partial differential equations, which determine the conservation equations for mass, momentum and energy, were solved using the finite element scheme based on Galerkin’s method. The analysis of heat transfer characteristics by forced convection was made by taking different values of the Reynolds number (Re between 10 and 100), Hartmann number (Ha between 0 and 100), nanoparticles concentration (φ between 0 and 0.1) and magnetic field inclination (γ between 0° and 90°); also, several fin positions α [0°–180°] were taken in the counter clockwise direction by a step of 5. After analysing the results, we concluded that Hartmann number, nanoparticles concentration, Reynolds number and magnetic field angles have an influence on the heat transfer rate. However, the fin position on the cylinder has a big impact on the Nusselt number and therefore on heat transfer quality. The best position of the fin is at (α = 150°), which gives the best Nusselt number and therefore the best heat trans-fer, but the fin position at (α = 0°) remains an unfavourable case that gives the lowest Nusselt values.

4

Acoustic excitation of electric field in water solution NaCl

Avrunin Oleg G., Bondarenko Igor S., Bondarenko Stanislav I., Kuzmenko Yulia V., Pinaieva Olga Yu., Kisała Piotr, Tleshova Akmaral, Luganskaya Saule

Przegląd Elektrotechniczny

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2019

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R. 95, nr 4

158--161

EN

The electric field value has been measured in an electroconducting water solution with NaCl, arising at simultaneously action on it of ultrasound and a direct magnetic field. Basic approaches and scheme of the laboratory device are proposed and designed. The basic characteristics of ultrasonic radiation in a place of measurement of electric field are defined, proceeding from its value and the experimental installation parameters. It is possible to assume, that at constant values of intensity of radiation and a magnetic field the value of measured voltage in the set areas of a body will give the new quantitative information on an organism state. Possibility of use of measurements of electric field for studying of properties of the biological tissue is discussed.

PL

Wartość pola elektrycznego została zmierzona w elektroprzewodzącym roztworze wodnym z NaCl, powstającym przy równoczesnym oddziaływaniu na nie ultradźwiękami i bezpośrednim polem magnetycznym. Zaproponowano i zaprojektowano podstawowe podejścia i schemat urządzenia laboratoryjnego. Określono podstawowe właściwości promieniowania ultradźwiękowego w miejscu pomiaru pola elektrycznego, wychodząc z jego wartości i eksperymentalnych parametrów instalacji. Można założyć, że przy stałych wartościach natężenia promieniowania i pola magnetycznego wartość mierzonego napięcia w zadanych obszarach ciała da nową informację ilościową o stanie organizmu. Omówiono możliwości wykorzystania pomiarów pola elektrycznego do badania właściwości tkanki biologicznej.

5

A locally modified single-phase model for analyzing magnetohydrodynamic boundary layer flow and heat transfer of nanofluids over a nonlinearly stretching sheet with chemical reaction

Akbarzadeh P.

Journal of Theoretical and Applied Mechanics

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2018

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Vol. 56 nr 1

81--94

EN

The problem of boundary layer flow and heat transfer of nanofluids over nonlinear stretching of a flat sheet in the presence of a magnetic field and chemical reaction is investigated numerically. In this paper, a new locally modified single-phase model for the analysis is introduced. In this model, the effective viscosity, density and thermal conductivity of the solid-liquid mixtures (nanofluids) which are commonly utilized in the homogenous single-phase model, are locally combined with the prevalent single-phase model. Similarity transformation is used to convert the governing equations into three coupled nonlinear ordinary differential equations. These equations depend on five local functions of the nanoparticle volume fraction viz., local viscosity ratio, magnetic, Prandtl, Brownian motion and thermophoresis functions. The equations are solved using Newton’s method and a block tridiagonal matrix solver. The results are compared to the prevalent single-phase model. In addition, the effect of important governing parameters on the velocity, temperature, volume fraction distribution and the heat and mass transfer rates are examined.

6

Entropy generation on MHD slip flow over a stretching cylinder with heat generation/absorption

Jain S., Bohra S.

International Journal of Applied Mechanics and Engineering

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2018

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Vol. 23, no. 2

413--428

EN

In the present study, we have investigated entropy generation on a magnetohydrodynamic fluid flow and heat transfer over a stretching cylinder with a porous medium in slip flow regime. A uniform heat source and radiation is also considered. Similarity transformation has been applied for making an ordinary differential equation from nonlinear governing partial differential equations. The numerical solution for the set of nonlinear ordinary differential equations has been obtained by using the fourth-order Runge-Kutta scheme together with the shooting method. The effects of pertinent parameters such as the magnetic field parameter, permeability parameter, slip parameter, Prandtl number and radiation parameter on the fluid velocity distribution, temperature distribution, entropy generation and Bejan number are discussed graphically.

7

Simultaneous effects of thermal radiation and chemical reaction on hydromagnetic pulsatile flow of a Casson fluid in a porous space

Kumar C. K., Srinivas S.

Engineering Transactions

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2017

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Vol. 65, iss. 3

461--481

EN

In the present study, the hydromagnetic pulsating flow of Casson fluid between two parallel plates in a porous space, thermal radiation and chemical reaction are investigated. The analytical solutions for flow variables are obtained by using a perturbation technique. The effects of pertinent parameters on velocity, temperature, concentration, Nusselt number and Sherwood number distributions are studied in detail.

8

Modelling Methods of Magnetohydrodynamic Phenomena Occurring in a Channel of the Device Used to Wash Out the Spent Automotive Catalyst by a Liquid Metal

Fornalczyk A., Przylucki R., Golak S., Willner J.

Archives of Metallurgy and Materials

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2016

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Vol. 61, iss. 2A

713--718

EN

The recovery of precious metals is necessary for environmental and economic reasons. Spent catalysts from automotive industry containing precious metals are very attractive recyclable material as the devices have to be periodically renovated and eventually replaced. This paper presents the method of removing platinum from the spent catalytic converters applying lead as a collector metal in a device used to wash out by using mangetohydrodynamic stirrer. The article includes the description of the methods used for modeling of magnetohydrodynamic phenomena (coupled analysis of the electromagnetic, temperature and flow fields) occurring in this particular device. The paper describes the general phenomena and ways of coupling the various physical fields for this type of calculation. The basic computational techniques with a discussion of their advantages and disadvantages are presented.

9

Exact solutions for the incompressible electrically conducting viscous flow between two moving parallel disks in unsteady magneto hydrodynamic and stability analysis

Balagondar P. M., Kempe Gowda M.

International Journal of Applied Mechanics and Engineering

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2013

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Vol. 18, no. 2

571--579

EN

The main interest of the present investigation is to generate exact solutions to the steady Navier-Stokes equations for the incompressible Newtonian viscous electrically conducting fluid flow motion and stability due to disks moving towards each other or in opposite directions with a constant velocity. Making use of the analytic solution, the description of possible conditions of motion is based on the exact solutions of the Navier-Stokes equations. Both stationary and transient cases have been considered. The stability of motion is analyzed for different initial perturbations. Different types of stability were found according to whether the disks moved towards or away from each other.

10

Flow of a magneto-micropolar fluid with temperature dependent viscosity and thermal conductivity past a continuously moving plate

Modather M., Abdou M.

International Journal of Applied Mechanics and Engineering

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2009

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Vol. 14, no 2

461-471

EN

A boundary layer analysis has been presented to study heat transfer with the effects of temperature dependent viscosity and thermal conductivity in the laminar, viscous, incompressible, electrically conducting, micropolar fluid past a continuously moving plate in the presence of a transverse magnetic field. The governing equations are transformed to dimensionless similarity boundary layer equations. Numerical solutions are given for the governing momentum, angular momentum and energy equations using the shooting method. The effects of the magnetic field parameter, the viscosity variation parameter, thermal conductivity variation parameter and micropolar parameter on the skin friction, wall couple stress and rate of heat transfer are discussed.

11

Unsteady MHD Couette Flow with Heat Transfer in the Presence of Uniform Suction and Injection

Attia H. A.

Mechanics and Mechanical Engineering

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2008

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Vol. 12, nr 2

165-170

EN

The unsteady Couette flow of an electrically conducting, viscous, incompressible fluid bounded by two parallel non-conducting porous plates is studied with heat transfer. An external uniform magnetic field and a uniform suction and injection are applied perpendicular to the plates while the fluid motion is subjected to a constant pressure gradient. The two plates are kept at different but constant temperatures while the Joule and viscous dissipations are included in the energy equation. The effect of the magnetic field and the uniform suction and injection on both the velocity and temperature distributions is examined.

12

Free convection effects on a perfectly conducting couple stress fluid

Ezzat M., Zakaria M., Samaan A., Abd-el Bary A.

Journal of Technical Physics

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2006

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Vol. 47, no 1

5-30

EN

We have introduced a magnetohydrodynamic model of boundary-layer equations for a perfectly conducting couple-stress fluid. This model is applied to study the effects of free convection currents with thermal relaxation on the flow of a polar fluid through a porous medium, which is bounded by a vertical plane surface. The state space formulation developed in EZZAT [1] and [2j is introduced. The formulation is valid for problems with or without heat sources. The resulting formulation, together with the Laplace transform technique, are applied to a variety of problems. The solution to a thermal shock problem and to the problem of the flow in the whole space with a plane distribution of heat sources are obtained. It is also applied to a semispace problem with a plane distribution of heat sources located inside the fluid. A numerical method is employed for the inversion of the Laplace transforms. The effects of Grashof number, material parameters, Alfven velocity, relaxation time, Prandtl number and the permeability parameter on the velocity, the temperature and the angular velocity distributions are discussed. The effects of cooling and heating of a couple-stress fluid have also been discussed. Numerical results are given and illustrated graphically for the problems considered.

13

Hall effects on MHD low and heat transfer over a stretching surface

Gupta A. S., Pal A., Pal B., Takhar H. S.

International Journal of Applied Mechanics and Engineering

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2003

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Vol. 8, no 2

219-232

EN

A magnetohydrodynamic (MHD) flow of an incompressible viscous electrically conducting fluid over a stretching surface is investigated when the fluid is permeated by a uniform transverse magnetic field and Hall effects are taken into account. It is found that for a flow at small magnetic Reynolds number past the surface which is stretched with a velocity proportional to the distance from a fixed point, velocity profiles are similar. For a fixed value of the Hall parameter m, components of velocity along and normal to the surface at a given point decrease with an increase in the magnetic parameter M. However for fixed values of m and M, the cross-flow velocity component induced by Hall currents reaches a maximum value at a certain height from the surface and the profiles for this velocity component shift towards the left with an increase in M. A novel result of the analysis is that for a fixed value of M, the primary velocity component remains positive for small values of the Hall parameter (m=<0.5) and becomes negative for m>0.5 indicating flow reversal. The region of this flow reversal increases with an increase in m. A similarity solution for temperature distribution in the above flow is also found and the rate of heat transfer at the stretching surface is computed for various values of m and M.

14

Shock waves in non-ideal fluids

Ojha S. N.

International Journal of Applied Mechanics and Engineering

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2002

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Vol. 7, no 2

445-464

EN

The problem of propagation of shock waves in non-ideal fluids has been discussed. In the course of discussion, the similarity solution method developed by Sedov has been used. The effects due to geometry of the motion, presence of magnetic field and rotation of the fluid on the propagation of shock waves have been discussed separately. The effects of radiation and viscosity have not been taken into account.

15

Magnetodynamic stability of bounded hollow jet pervaded by varying magnetic field

Radwan A. E., Elazab S. S., Hydia W. M.

Mechanics and Mechanical Engineering

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2000

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Vol. 4, nr 2

213--223

EN

The problem is formulated and solved based on the linear perturbation technique. The stability criterion is derived and discussed. The analytical results are confirmed numerically. The uniform magnetic fields interior and exterior the jet have stabilizing influences for all modes of perturbation. The varying transverse magnetic field interior the model is stabilizing or not according to restrictions. The radii ratio of the gas-liquid cylinder has a tendency for stabilizing the model. As the axial magnetic fields intensities interior and exterior the gas jet are so much strong than that of the transverse magnetic field and adapting the cylinders radii ratio the instability of the model is suppressed and stability sets in.