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1

Analysis of factors affecting destabilization of a viscous liquid flow in channels

Mamedov Asiman, Hnativ Roman, Yakhno Oleg, Murashchenko Alena

International Journal of Applied Mechanics and Engineering

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2023

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Vol. 28, no. 3

86--100

EN

An analysis of the influence of inertia forces and ponderomotive forces on the destabilization of the flow of viscous fluids in the hydrodynamic initial section is given. Cases of flow of viscous, anomalously viscous and electrically conductive liquids are considered; the degree of influence of mass forces on the destabilization of the flow is estimated. As applied to the flow in the hydrodynamic initial section, the degree of influence of inertia forces from convective acceleration and forces with a magnetic nature can be different. Inertia forces stimulate the accelerated movement of the fluid, and in the case of forces with a magnetic nature, ponderomotive forces contribute to deceleration, which is confirmed by the results of studies of the velocity field. Recommendations are given for calculating the length of the hydrodynamic initial section in the presence of mass forces with different nature.

2

Numerical solution of MHD channel flow in a porous medium with uniform suction and injection in the presence of an inclined magnetic field

Chutia Muhim

Journal of Applied Mathematics and Computational Mechanics

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2022

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Vol. 21, nr 2

5--13

EN

In this paper, the steady fully developed MHD flow of a viscous incompressible electrically conducting fluid through a channel filled with a porous medium and bounded by two infinite walls is investigated numerically for the cases (i) Poiseuille flow and (ii) Couette-Poiseuille flow; with uniform suction and injection at the walls in the presence of an inclined magnetic field. The Brinkman equation is used for the flow in the porous channel and solved numerically using the finite difference method. Numerical results are obtained for velocity. The effects of various dimensionless parameters such as Hartmann number (M), suction/injection parameter (S), permeability parameter (α) and angle of inclination (θ) on the flow are discussed and presented graphically.

3

Role of sudden application or withdrawal of magnetic field on MHD Couette flow

Jha B. K., Oni M. O.

International Journal of Applied Mechanics and Engineering

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2019

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Vol. 24, no. 4

92--105

EN

This article investigates the impact of a sudden application or sudden withdrawal of a magnetic field on an unsteady MHD Couette flow formation in a parallel plate channel. The governing momentum equation is derived and solved exactly in Laplace domain using the Laplace transform technique with the necessary initial and boundary conditions to capture the present physical situation for the cases; sudden application or sudden withdrawal of a magnetic field. Due to the complexity of the solution obtained, the Riemann-sum approximation technique is used to transform the Laplace domain to time domain. During the course of graphical and tabular representations, results show that the Hartmann number, time and nature of application of a magnetic field play an important role in the transition from hydrodynamic to magnetohydrodynamic flow and vice-versa. Also, fluid velocity steady-state solution is independent on whether the magnetic field is fixed relative to the moving plate or to the fluid for sudden withdrawal of magnetic field. In addition, the application of a sudden magnetic field leads to a delay in the attainment of steady-state solution.

4

Entropy analysis of third-grade MHD convection flows from a horizontal cylinder with slip

Madhavi K., Prasad V. R., Gaffar S. A., Venkatadri K.

Archive of Mechanical Engineering

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2018

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Vol. LXV, nr 3

417--440

EN

In thermos ﬂuid dynamics, free convection ﬂows external to diﬀerent geometries, such as cylinders, ellipses, spheres, curved walls, wavy plates, cones, etc., play major role in various industrial and process engineering systems. The thermal buoyancy force associated with natural convection ﬂows can play a critical role in determining skin friction and heat transfer rates at the boundary. In thermal engineering, natural convection ﬂows from cylindrical bodies has gained exceptional interest. In this article, we mathematically evaluate an entropy analysis of magnetohydrodynamic third-grade convection ﬂows from permeable cylinder considering velocity and thermal slip effects. The resulting non-linear coupled partial diﬀerential conservation equations with associated boundary conditions are solved with an eﬃcient unconditionally stable implicit ﬁnite diﬀerence Keller-Box technique. The impacts of momentum and heat transport coeﬃcients, entropy generation and Bejan number are computed for several values of non-dimensional parameters arising in the ﬂow equations. Streamlines are plotted to analyze the heat transport process in a two-dimensional domain. Furthermore, the deviations of the ﬂow variables are compared with those computed for a Newtonian ﬂuid and this has important implications in industrial thermal material processing operations, aviation technology, diﬀerent enterprises, energy systems and thermal enhancement of industrial ﬂow processes.

5

Study of an oxygenation process in capillary in the presence of magnetic field

Bali R., Awasthi U., Sharma S. K.

International Journal of Applied Mechanics and Engineering

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2011

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Vol. 16, no 2

331-344

EN

A mathematical model for the transport of oxygen in the systemic capillaries and the surrounding tissue in the presence of a magnetic field is presented in this paper. We have modeled the capillary by a circular cylinder surrounded by a tissue of uniform thickness. The model takes into account the transport mechanisms of molecular diffusion, convection and diffusion due to the presence of hemoglobin as a carrier of the gases (oxygen).The resulting system of differential equations is solved analytically by the method of separation of variable and Picard's method. The result for partial pressure of oxygen in the capillary and tissue region is obtained. The effect of the Hartmann number (H) and others parameters is obtained and discussed through graphs.

6

Hall effects on oscillatory Couette flow

Ghara N., Maji S. L., Das S., Jana R. N.

International Journal of Applied Mechanics and Engineering

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2011

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Vol. 16, no 4

1005-1020

EN

Hall effects on the oscillatory Couette flow between two horizontal parallel plates are studied. One of the plate is at rest and the other one oscillates in its own plane. The effects of Hall and frequency parameters on the velocities and the shear stresses for the steady and unsteady flows are analyzed. It is found that the shear stresses at the M stationary plate due to the unsteady primary and secondary velocities have a phase lag over the plate oscillations for those values of the Hall parameter m, Hartmann number and the frequency parameter , we have considered.

7

On pulsatile hydromagnetic flow of an oldroyd fluid with heat transfer

Srinivas S., Malathy T., Sachdev P. L.

Engineering Transactions

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2007

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Vol. 55, iss. 1

79-94

EN

The problem of heat transfer to pulsatile flow of hydromagnetic viscoelastic fluid has been studied. Expressions for the velocity, temperature distribution and mass flow rate are obtained. The rate of heat transfer at the plates has also been calculated. These expressions are evaluated numerically for various values of the parameters. The influence of pertinent parameters on temperature, heat transfer coefficient and mass flux has been studied and numerical results obtained are presented graphically.