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1
Content available Effect of MHD on unsteady oscillatory Couette flow through porous media
Sharma Bhupendra K., Sharma Pawan Kumar, Cauhan Sudhir Kumar
International Journal of Applied Mechanics and Engineering
|
2022
|
Vol. 27, no. 1
188--202
EN
This paper describes the effects of a magnetic field on unsteady free convection oscillatory systems. When temperature and species concentration fluctuate with time around a non-zero constant, "Couette flow" across a porous medium occurs. The system of non-linear ODEs that governs the flow is solved analytically using the perturbation approach because the amplitude of fluctuations is very tiny. Mean flow and transient velocity, transient concentration, transient temperature, heat transfer, mean skin friction and phase and amplitude of skin friction. All have approximate solutions. The influence of different parameters on flow characteristics has been specified and discussed.
2
Content available Thermal radiation and chemical reaction effects on unsteady magnetohydrodynamic third grade fluid flow between stationary and oscillating plates
Idowu A. S., Sani U.
International Journal of Applied Mechanics and Engineering
|
2019
|
Vol. 24, no. 2
269--293
EN
An analysis was carried out for an unsteady magnetohydrodynamic (MHD) flow of a generalized third grade fluid between two parallel plates. The fluid flow is a result of the plate oscillating, moving and pressure gradient. Three flow problems were investigated, namely: Couette, Poiseuille and Couette-Poiseuille flows and a number of nonlinear partial differential equations were obtained which were solved using the He-Laplace method. Expressions for the velocity field, temperature and concentration fields were given for each case and finally, effects of physical parameters on the fluid motion, temperature and concentration were plotted and discussed. It is found that an increase in the thermal radiation parameter increases the temperature of the fluid and hence reduces the viscosity of the fluid while the concentration of the fluid reduces as the chemical reaction parameter increases.
3
Content available 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
|
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
Content available Unsteady MHD heat transfer in Couette flow of water at 4°c in a rotating system with ramped temperature via finite element method
Reddy G. J., Raju R. S., Rao J. A., Gorla R. S. R.
International Journal of Applied Mechanics and Engineering
|
2017
|
Vol. 22, no. 1
145--161
EN
An unsteady magnetohydromagnetic natural convection on the Couette flow of electrically conducting water at 4°C (Pr = 11.40) in a rotating system has been considered. A Finite Element Method (FEM) was employed to find the numerical solutions of the dimensionless governing coupled boundary layer partial differential equations. The primary velocity, secondary velocity and temperature of water at 4°C as well as shear stresses and rate of heat transfer have been obtained for both ramped temperature and isothermal plates. The results are independent of the mesh (grid) size and the present numerical solutions through the Finite Element Method (FEM) are in good agreement with the existing analytical solutions by the Laplace Transform Technique (LTT). These are shown in tabular and graphical forms.
5
Content available The effect of MHD on free convection with periodic temperature and concentration in the presence of thermal radiation and chemical reaction
Zigta P., Koya P. R.
International Journal of Applied Mechanics and Engineering
|
2017
|
Vol. 22, no. 4
1059--1073
EN
This paper studies the effect of magneto hydrodynamics on unsteady free convection between a pair of infinite vertical Couette plates. The temperature of the plates and concentration between the plates vary with time. Convection between the plates is considered in the presence of thermal radiation and chemical reaction. The solution is obtained using perturbation techniques. These techniques are used to transform nonlinear coupled partial differential equations to a system of ordinary differential equations. The resulting equations are solved analytically. The solution is expressed in terms of power series with some small parameter. The effect of various parameters, viz., velocity, temperature and concentration, has been discussed. Mat lab code simulation study is carried out to support the theoretical results. The result shows that as the thermal radiation parameter R increases, the temperature decreases near the moving porous plate while it approaches to a zero in the region close to the boundary layer of the stationary plate. Moreover, as the modified Grashof number, i.e., based on concentration difference, increases, the velocity of the fluid flow increases hence the concentration decreases. An increase in both the chemical reaction parameter and Schmidt number results in decreased concentration.
6
Content available Transient velocity and steady state entropy generation in a microfluidic Couette flow containing charged nano particles
Gorla R. S. R., Gireesha B. J.
International Journal of Applied Mechanics and Engineering
|
2015
|
Vol. 20, no. 4
787--804
EN
An analysis has been provided to determine the transient velocity and steady state entropy generation in a microfluidic Couette flow influenced by electro-kinetic effect of charged nanoparticles. The equation for calculating the Couette flow velocity profile is derived for transient flow. The solutions for momentum and energy equations are used to get the exact solution for the dimensionless velocity ratio and dimensionless entropy generation number. The effects of the dimensionless entropy generation number, Bejan number, irreversibility ratio, entropy generation due to fluid friction and due to heat transfer on dimensionless time, relative channel height, Brinkman number, dimensionless temperature ratio, nanoparticle volume fraction are analyzed.
7
Content available Application of HPM to find analytical solution of coette flow with variable viscosity
Azimi A., Azimi M., Javanfar A.
Acta Mechanica et Automatica
|
2015
|
Vol. 9, no. 1
5--8
EN
In this paper, the couette flow of fluid with variable viscosity is studied analytically by using Homotopy Pertubation Method (HPM). At first the basic idea of Homotopy Pertubation Method (HPM) is presented. The mathematical formulation and application of HPM to nonlinear problem are presented in section three. In order to check the validity of solution the analytical results are compared with exact ones for various numerical cases. The good agreement between exact method and Homotopy Pertubation Method has been assures us about the solution accuracy.
8
Content available Unsteady hydromagnetic Couette flow due to ramped motion of one of the porous plates
Jha B. K., Jibril H. M.
International Journal of Applied Mechanics and Engineering
|
2013
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Vol. 18, no. 4
1039--1056
EN
An unsteady flow formation in Couette motion of an electrically conducting fluid subject to transverse magnetic field has been analyzed in the presence of suction/injection through the porous plates when one of the porous plates is in ramped motion. It is assumed that the porous plates are uniformly permeable and the fluid is entering the flow region through one of the porous plates at same rate as it is leaving through the other porous plate. The resulting boundary value problem has been solved exactly under the assumption of a negligible induced magnetic field, external electric field and pressure gradient. Unified closed form expressions for the velocity field and skin-friction corresponding to the case of a magnetic field fixed relative to the fluid or to the moving porous plate have been presented. In order to highlight the impact of the ramp motion of the porous plate on the fluid flow, it has also been compared with Couette flow between porous plates when one of the porous plates has been set into an impulsive motion.
9
Content available Three-dimensional oscillating flow between two parallel plates through a porous medium
Guria M., Ghara N., Jana R. N.
International Journal of Applied Mechanics and Engineering
|
2013
|
Vol. 18, no. 4
1025--1037
EN
An unsteady Couette flow between two parallel plates when upper plates oscillates in its own plane and is subjected to a constant suction and the lower plate to a injection velocity distribution through the porous medium has been analyzed. The approximate solution has been obtained using perturbation technique. It is seen that the primary velocity increases whereas the secondary velocity decreases with an increase in permeability parameter. It is also found that the primary velocity increases with an increase in the Reynolds number as well as the suction parameter. The magnitude of the secondary velocity increases near the stationary plate but decreases near the oscillating plate with an increase in the Reynolds number. Whereas, it increases with an increase in the suction parameter.
10
Content available remote Unsteady MHD Couette flow of class-II of a viscous incompressible electrically conducting fluid in a rotating system
Seth G. S., Singh J. K.
International Journal of Applied Mechanics and Engineering
|
2012
|
Vol. 17, no. 2
495-512
EN
An unsteady hydromagnetic Couette flow of class-II of a viscous incompressible electrically conducting fluid in a rotating system is studied. The fluid flow within the channel is induced due to non-torsional oscillations of the upper plate of the channel. An exact solution of the governing equations is obtained by the Laplace transform technique. The numerical solution of the fluid velocity is depicted graphically whereas numerical values of shear stress at the plates are presented in a tabular form for various values of the magnetic parameter, rotation parameter and frequency parameter.
11
Content available remote Time dependent MHD Couette flow due to ramped motion of one of the boundaries
Jha B. K., Jibril H. M.
International Journal of Applied Mechanics and Engineering
|
2012
|
Vol. 17, no. 2
383-399
EN
The effects of a transverse magnetic field on the Couette flow of an electrically conducting fluid between two infinite parallel plates have been discussed when one of the plates has been set into ramped motion. Under the assumption of a negligible induced magnetic field and applied magnetic field being fixed relative to the fluid or moving plate, the governing momentum equation has been solved exactly. The expressions for velocity field and skin-friction have been presented. The transient features of velocity and skin-friction have been discussed for different values of the Hartmann number. It is seen that the velocity field and skin-friction increases with an increase of the Hartman number when the magnetic field is fixed with respect to the moving plate while the result is just reverse when it is fixed with respect to the fluid.
12
Content available remote Unsteady MHD Couette flow through a porous medium in a rotating system
Kumar N., Gupta S.
International Journal of Applied Mechanics and Engineering
|
2011
|
Vol. 16, no 4
1037-1049
EN
An unsteady hydromagnetic Couette flow of a viscous incompressible fluid through a porous medium overcrowded between parallel porous non-conducting plates, rotating with a uniform angular velocity about an axis normal to the plates is considered. The flow is generated by the motion of the upper plate. The fluid and plates rotate in unison with the same angular velocity. An exact solution of governing equations is obtained by using the Laplace transform. Solutions for velocity distributions as well as the coefficient of skin-friction are obtained and their profiles for various values of physical parameters are shown through graphs.
13
Content available remote Hall effects on oscillatory Couette flow
Ghara N., Maji S. L., Das S., Jana R. N.
International Journal of Applied Mechanics and Engineering
|
2011
|
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.
14
Content available remote Effects of Hall current on unsteady hydromagnetic Couette flow in a rotating system induced by an accelerated movement of one of the plates of the channel in the presence of an inclined magnetic field
Seth G. S., Nandkeolyar R., Ansari M. S.
International Journal of Applied Mechanics and Engineering
|
2011
|
Vol. 16, no 3
835-849
EN
Effects of Hall current on an unsteady hydromagnetic Couette flow, induced due to an accelerated movement of the lower plate of the channel in a rotating system when the fluid flow is permeated by an inclined magnetic field is studied. An exact solution for the fluid velocity is obtained by the Laplace transform technique. The expression for the shear stress at the moving plate is also derived. An asymptotic behavior of the solution is analyzed for small and large values of time to gain some physical insight into the flow-pattern. It is found that Hall current, rotation and angle of inclination of the magnetic field tend to accelerate fluid flow in both the primary and secondary flow directions, whereas the magnetic field has a tendency to retard fluid flow in both the primary and secondary flow directions.
15
Content available remote Effect of radiation on temperature distribution in three-dimensional Couette flow with heat source/sink
Sharma B. K., Sharma P. K., Chand T.
International Journal of Applied Mechanics and Engineering
|
2011
|
Vol. 16, no 2
531-542
EN
An analysis of a three-dimensional Couette flow with radiation effect on temperature distribution in the presence of heat source/sink is analysed, when the injection of the fluid at the lower stationary plate is transverse sinusoidal and its corresponding removal by constant suction through the porous plate in uniform motion. Due to this type of injection the flow velocity becomes three-dimensional. The effect of the Prandtl number, injection and source/sink parameters on the rate of heat transfer is examined. The Prandtl number has a much greater effect on the temperature distribution than the injection or source/sink parameters.
16
Content available remote Time dependent natural convection Couette flow of heat generating/absorbing fluid: accelerated motion
Jha B. K., Ajibade A. O.
International Journal of Applied Mechanics and Engineering
|
2010
|
Vol. 15, no 4
1083-1100
EN
The unsteady Couette flow in a channel formed by two vertical parallel plates is investigated in the presence of internal heat generation/absorption. The flow is set up due to time dependent motion of one of the plates coupled with asymmetric heating of the infinite vertical parallel plates. Analytical solutions of the resulting partial differential equations are obtained using the Laplace transforms technique. The numerical values obtained from the analytical expressions for temperature, velocity, Nusselt number, skin-friction and mass flux are presented graphically to study the flow behaviour in the presence of the governing parameters. It is interesting to note that in the absence of convection currents (Gr=0) the flow is dependent only on the motion of one of the channel plates. The influence of the heat generation/absorption parameter on the rate of heat transfer on one plate is the exact opposite of the influence on the other plate while its influence on the skin-friction is identical on both plates. In the presence of external cooling, the mass flux diverges as time increases, while it converges to zero in the case of external heating.
17
Content available remote A note on a magnetohydrodynamic Couette flow of viscous incompressible non-Newtonian fluids
Amattat M.
International Journal of Applied Mechanics and Engineering
|
2010
|
Vol. 15, no 4
1287-1295
EN
This note is devoted to a mathematical study of a phenomenon of dead core which appears in a magnetohydrodynamic Couette flow. For this purpose, let us start by giving some considerations on the notion of Newtonian fluids.
18
Content available remote On three dimensional free convection Couette flow with transpiration cooling and temperature jump boundary conditions
Jain N. C., Sharma B.
International Journal of Applied Mechanics and Engineering
|
2009
|
Vol. 14, no 3
715-732
EN
A study of the temperature jump boundary condition is made on a three dimensional free convection flow between two vertical parallel porous flat plates. At the stationary plate there is a transverse sinusoidal injection and its corresponding removal is at the other plate. Using series expansion, the expressions for velocity and temperature distributions, the skin friction and rate of heat transfer are obtained. It is observed that an increase in the jump temperature increases the Nusselt number at the stationary plate.
19
Content available remote Unsteady MHD Couette Flow with Heat Transfer in the Presence of Uniform Suction and Injection
Attia H. A.
Mechanics and Mechanical Engineering
|
2008
|
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.
20
Content available remote Characterization of the viscous behavior of compacted ceramic particles under shear and pressure loads
Zhou F., Advani S. G., Wetzel E. D.
International Journal of Applied Mechanics and Engineering
|
2005
|
Vol. 10, no 3
505-514
EN
Two different viscometer systems are designed and fabricated to characterize the behavior of ceramic particles under shear stress and high pressures. The first system is a Couette flow device with ability to exert pressure on the particles during its rotation and measure the torque and angular velocity of the system. From this information we can calculate viscosity and energy dissipation due to friction between particles as a function of the shear rate. The second system focuses on the movement of a cylinder through a bed of compacted ceramic particles. By measuring the force required to move the cylinder through the compacted bed, we can evaluate the effective resistance of the particle bed under various compaction pressures. This characterization should prove useful in understanding the shearing and dissipation mechanisms between granular particles under high pressures.
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