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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 remote Entropy analysis of a variable viscosity MHD Couette flow Between two concentric pipes with convective cooling
Makinde Oluwole Daniel, Eegunjobi Adetayo Samuel
Engineering Transactions
|
2020
|
Vol. 68, iss. 4
317--334
EN
This paper addresses the combined effects of the magnetic field, thermal buoyancy force, viscous dissipation, Joule heating and temperature-dependent viscosity on the Couette flow of an incompressible conducting fluid between two concentric vertical pipes. It is assumed that convective cooling occurs at the surface of the outer moving pipe while the surface of the inner fixed pipe is maintained at a constant temperature. The nonlinear equations for momentum and energy are obtained and solved numerically using a shooting method coupled with the Runge-Kutta-Fehlberg integration procedure. Relevant results depicting the effects of embedded thermophysical parameters on the velocity and temperature profiles, skin friction, the Nusselt number, entropy generation rate and the Bejan number are presented graphically and discussed. It is found that an increase in the magnetic field intensity boosts the entropy generation rate while an increase in convective cooling lessens it.
3
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
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2017
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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.
4
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
|
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.
5
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.
6
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.
7
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.
8
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.
9
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.
10
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
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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.
11
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.
12
Content available remote Effect of wall conductance on MHD Couette flow and heat transfer in a rotating system
Guria M., Jana R. N., Ghosh S. K.
International Journal of Applied Mechanics and Engineering
|
2008
|
Vol. 13, no 1
75-90
EN
The effect of wall conductance on the hydromagnetic Couette flow and heat transfer between two parallel plates in a rotating frame of reference in the presence of an applied uniform transverse magnetic field is studied. An exact solution of the goveming equations has been obtained. It is found that both the primary and the secondary velocities decrease with an increase in wall conduetance parameter. It is also found that the induced magnetic field components increase with an increase in wall conduetance parameter. The shear stresses at the lower plate decrease with an increase in wall conductivity. The heat transfer characteristic has also been studied on taking viscous and Joule dissipation into account.
13
Content available remote Three dimensionaI oscillating flow between two parallel plates with heat transfer
Guria M., Jana R. N.
International Journal of Applied Mechanics and Engineering
|
2007
|
Vol. 12, no 1
19-35
EN
The unsteady viscous incompressible Couette flow between two parallei plates when the upper plate oscillates in its own piane and is subjected to a constant suction whereas the lower plate is subjected to a suction velocity distribution has been theoretically analyzed. An approximate solution has been obtained using perturbation technique. It is found that the main flow velocity increases with an increase in the Reynolds number as well as suction parameter but it decreases with an increases in the frequency parameter. It is also shown that with an increase in the Reynolds number, the magnitude of the cross velocity increases near the stationary plate but decreases near the oscillating plate. On the other hand, it increases with an increase in the suction parameter. The heat transfer characteristic has also been studied by taking viscous dissipation into account. It is found that the temperature increases with an increase in the Reynolds number as well as the Prandtl number but it decreases with an increase in the frequency parameter.
14
Content available remote Unsteady Couette-Poiseulle Flow with Variable Physical Properties in the Presence of a Uniform Magnetic Field
Attia H. A.
Mechanics and Mechanical Engineering
|
2005
|
Vol. 9, nr 2
5--13
EN
The unsteady hydromagnetic Couette-Poiseulle flow and heat transfer of an electrically conducting fluid is studied in the presence of a transverse uniform magnetic field with variable physical properties. The viscosity and thermal conductivity of the fluid are assumed to vary with temperature. The fluid is subjected to a constant pressure gradient and an external uniform magnetic field perpendicular to the plates which are kept at different but constant temperatures. The effect of the magnetic field, the temperature dependent viscosity and thermal conductivity on both the velocity and temperature fields is reported.
15
Content available remote Mixed Convection on a Vertical Flat Plate with Variable Magnetic Field
Dimian M. F., Hadhoda M. Kh.
Mechanics and Mechanical Engineering
|
2005
|
Vol. 9, nr 2
15--28
EN
The steady laminar incompressible boundary layer mixed convection flow of an electrically conducting fluid on a vertical flat plate in the presence of an applied magnetic field has been studied. The effect of the induced magnetic field has been considered in the analysis. The resulting partial differential equations are transformed into a system of ordinary differential equations which have been solved numerically using shooting method. Two cases are considered here for the buoyancy force: (i) when it acts in the same direction as the forced flow (Tω > T∞), (ii) when it acts in the opposite direction to the forced flow (Tω < T∞). The velocity profiles, temperature profiles, the skin friction on the plate and the rate of heat transfer coefficient (Nusselt number) are computed and discussed for different values of the magnetic force number β, the thermal buoyancy force ╏, reciprocal of the magnetic Prandtl number a and viscous dissipation parameter (Eckert number) Ec for the two cases.
16
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.
17
Content available remote A note on the flows of inhomogeneous fluids with shear-dependent viscosities
Anand M., Rajagopal K. R.
Archives of Mechanics
|
2005
|
Vol. 57, nr 5
417--428
EN
Inhomogenous fluids have not been studied with the intensity that they deserve. In fact, many studies that are supposedly concerned with the response of inhomogeneous fluids are not directed at inhomogeneous fluids, and this stems from not recognizing the fact that the properties of a fluid varying in its current configuration does not mean that the fluid is inhomogeneous. Here, we show that mild variations in the properties of the fluid which might warrant it being approximated as a homogeneous fluid with average properties could lead to significant errors in the computation of both global and local quantities, associated with the flow.
18
Content available remote Obliczenia przepływu metodą cząstek rozmytych
Pozorski J., Wawreńczuk A.
Zeszyty Naukowe. Cieplne Maszyny Przepływowe - Turbomachinery / Politechnika Łódzka
|
2000
|
nr 117, vol. 1
59-64
PL
Podjęto obliczenia numeryczne przepływu lepkiego nieściśliwego metodą cząstek. Omówiono podstawy metody cząstek rozmytych (SPH - Smoothed Particle Hydrodynamics) od niedawna rozwijanej w mechanice płynów, a także własną modyfikację metody dla przepływów nieściśliwych. Przedstawiono wyniki dla prostych przepływów nieustalonych oraz dla przepływu w prostokątnym zagłębieniu generowanego ruchem ścianki.
EN
A numerical computation of viscous incompressible flows using a particle method is addresed. Underlying concepts of the relatively recent method of smoothed particle hydrodynamics (SPH) are recalled. Developments for incompressibility constraint are reported. Presented results include simple unsteady flows and the lid-dnven cavity flow.
19
Effects of the side walls in generalized Couette flow
Erdogan M. E.
Applied Mechanics and Engineering
|
1998
|
Vol. 3, no 2
271-286
EN
The effects of the side walls on the flow of an incompressible viscous fluid in a conduit of rectangular cross-section by the combined effect of the velocity of the top wall and a constant pressure gradient along the conduit are considered. For this purpose, four different flow conditions are used. In the first case, a separation occurs at the bottom wall. In the second case, the volume flux is zero. In the third case, a separation occurs at the top wall. In the fourth case, the flow is set up by the motion of the top wall in the absence of the pressure gradient. Furthermore, the effect of the side walls in a channel of rectangular cross-section is discussed.
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