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1
Content available remote Steady axisymmetric flow and heat transfer of micropolar fluid over a vertical permeable slender cylinder in the presence of thermal radiation
Mansour M. A., Mohamed R. A., Abd Elaziz M. M., Ahmed S. E.
International Journal of Applied Mechanics and Engineering
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2010
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Vol. 15, no 4
1185-1203
EN
The effects of thermal radiation and suction/blowing on an axisymmetric flow and heat transfer of a micropolar fluid over a vertical slender cylinder are analyzed. The partial differential equations governing the flow and heat transfer have been transformed to ordinary differential equations by using similarity transformations which are then solved numerically. The numerical results are validated by favorable comparisons with previously published results. The cases of buoyancy-assisted flow, pure mixed convection, buoyancy opposed flow, permeable cylinder, impermeable cylinder, Newtonian fluids and non-Newtonian fluids as well as the case which represents concentrated particle flow in which the microelements close to the wall surface are unable to rotate and the case which indicates vanishing of an antisymmetric part of the stress tensor are considered. A parametric study of the governing parameters, namely the buoyancy parameter, suction/injection parameter, radiation parameter, vortex viscosity parameter, curvature parameter and microgyration boundary conditions parameter on the linear velocity, angular velocity and temperature as well as the wall stress, wall couple stress and the rate of heat transfer is conducted. A selected set of numerical results is presented graphically and discussed.
2
Content available remote Thermal non-equilibrium model for mhd micropolar free convection from elliptic cylinders in a porous medium
Mansour M. A., Gorla R. S. R., Abd El-Aziz M. M., Ahmed S. E.
International Journal of Applied Mechanics and Engineering
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2009
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Vol. 14, no 2
443-459
EN
This work uses a thermal non-equilibrium model to study the free convection boundary layer flow from cylinders of elliptic cross-section with uniform suction or injection in a micropolar fluid through a porous medium in the presence of a uniform magnetic field. The transformed conservation equations of the nonsimilar boundary layers are solved numerically by the shooting technique with a fourth-order Runge-Kutta integration scheme and the results compare very well with published results. The results obtained are displayed graphically to illustrate the influences of different physical parameters on the local heat transfer rate (Nusselt number) for the fluid and solid phases, velocity, angular velocity and streamlines.
3
Content available remote Some free convection flows over a stretching cone embedded in porous media
Mansour M. A., Aly A. M., El-Anssary N. F.
International Journal of Applied Mechanics and Engineering
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2009
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Vol. 14, no 3
799-812
EN
Laminar free convection from a stretching cone embedded in porous media with the effects of pressure work and chemical reaction is considered. The governing partial differential equations have been transformed by a similarity transformation into a system of ordinary differential equations, which are solved numerically using a fourth order Runge-Kutta scheme with the shooting method. The results are displayed graphically to illustrate the influences of the parameters characterizing the chemical reaction parameter, pressure work parameter and buoyancy ratio on the velocity, temperature and concentration fields for boundary conditions, namely an isothermal surface, a uniform heat surface and a vertical adiabatic surface.
4
Content available remote Effect of heat and mass transfer on free convection flow over a cone with uniform suction or injection in micropolar fluids
El-Kabeir S. M., Modather M., Mansour M. A.
International Journal of Applied Mechanics and Engineering
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2006
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Vol. 11, no 1
15-35
EN
A regular perturbation is presented to study the effect of heat and mass transfer on free convection flow with a uniform suction and injection over a cone in a micropolar fluid. The velocity, temperature, concentration and microrotation profiles were computed for various values of suction/injection, Schmidt number and micropolar parameters. The governing equations are first cast into a dimensionless form by a nonsimilar transformation and the resulting equations are then solved numerically by using the Runge-Kutta numerical integration, the procedure in conjunction with the shooting technique. The results indicate that as the micropolar parameter increases the wall couple stress, the shear stress, the Nusselt number and Sherwood number decrease with it. While the Shmidt number increases the shear stress, the wall couple stress and Nusselt number decrease, the opposite is true for the Sherwood number. The results are shown in figures and tables followed by a quantitative discussion.
5
Content available remote Thermal-radiation effects on forced convection heat transfer on a flat plate embedded in porous media for power-law fluids
Mansour M. A., El-Shaer N. A.
International Journal of Applied Mechanics and Engineering
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2004
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Vol. 9, no 4
715-723
EN
An analysis is presented to investigate the combined effect of the thermal radiation and the presence of an isotropic solid matrix on the forced convection heat transfer rate from a flat plate to a power-law non-Newtonian fluid saturated porous medium. The Forchheimer extension is also considered in the flow equations. The rosseland approximation is used to describe the radiative heat flux in the energy equation. Numerical results are presented for the velocity distribution and temperature profiles within the boundary layer. The effects of the flow index, radiation, first and second-order resistance on the velocity, and temperature profiles are discussed. The missing wall values of the velocity and thermal functions are tabulated.
6
Content available remote Combined thermal and diffusion buoyancy effects in micropolar fluids
Mansour M. A., Mohammadein A. A., El Kabeir S. M., Gorla R. S. R.
International Journal of Applied Mechanics and Engineering
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2001
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Vol. 6, no 2
551-572
EN
A regular perturbation analysis is presented for the laminar natural convection flows of micropolar fluids with temperature dependent viscosity: a freely-rising plane plume, the flow above a horizontal line source on an adiabatic surface (a plan wall plume) and the flow adjacent to a vertical uniform flux surface. While these flows have well-known power-law similarity solutions when the fluid viscosity is taken to be constant, they are non-similar when the viscosity is considered to be a function of temperature. A flow adjacent to a vertical isothermal surface is also analyzed for comparison in order to estimate the extent of validity of the perturbation analysis. The formulation used here provides a unified treatment of variable viscosity effects on those four flows. Computed first-order perturbation quantities are presented for all four flows. The velocity, microrotation distribution, temperature and concentration profiles are shown. Numerical results are presented for the local Nusselt number and Sherwood number, wall shear stress and wall couple stress.
7
Thermal dispersion effects on non-Darcy axisymmetric free convection in a saturated porous medium with lateral mass transfer
Mansour M. A., El-Amin M. F.
Applied Mechanics and Engineering
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1999
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Vol. 4, no 4
727-737
EN
An analysis is presented to study the effects of thermal dispersion and lateral mass flux on non-Darcy axisymmetric free convection on permeable horizontal surfaces in a fluid saturated porous medium. The thermal diffusivity coefficient has been assumed to be the sum of the molecular diffusivity and the dynamic diffusivity due to mechanical dispersion. Similarity solutions are obtained when the surface temperature varies as the square root of the radial distance or when heat flux is constant. The effects of the dispersion, lateral mass flux and non-Darcy parameters on the velocity and temperature are shown on graphs. The numerical values of the rate of heat transfer as well as the total energy convected through the boundary layer are entered in tables.
8
The influence of surface mass flux on mixed convection in non-newtonian fluids along a vertical plate in a porous medium
Mansour M. A.
Applied Mechanics and Engineering
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1999
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Vol. 4, no 1
133-147
EN
The problem of mixed convection in power-law type non-Newtonian fluids along a non-isothermal vertical plate with surface mass transfer is investigated. The transformed conservation laws are solved numerically for the case of variable wall temperature conditions. Numerical results are presented for the details of the velocity and temperature fields. A discussion is provided for the effect of suction and injection as well as the viscosity index on the surface heat transfer rate.
9
Radiative and variable viscosity effects on a free convection flow over a vertical stretching surface
Mansour M. A., Gorla R. S. R.
Applied Mechanics and Engineering
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1999
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Vol. 4, no 2
191-201
EN
The effects of radiation and variable viscosity on natural convection heat transfer from a vertical stretching sheet with surface mass transfer is analysed. A three dimensional similarity solution to the governing momentum and energy equations is presented. Numerical data for the friction and Nusselt number have been tabulated.
10
Nonsimilar boundary layer solutions for mixed convection in non-Newtonian fluids along a vertical plate in a porous medium
Mansour M. A., Gorla R. S. R.
Applied Mechanics and Engineering
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1999
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Vol. 4, no 4
715-726
EN
Nonsimilarity solutions for mixed convection in power-law type non-Newtonian fluids from a vertical flat plate embedded in a porous medium are reported for a variable wall temperature of the power law form. The governing equations, including internal heat generation, are first transformed into a dimensionless form by the nonsimilar transformation and then solved by a finite-difference scheme. Numerical results are presented for the fluid velocity and temperature fields.
11
Micropolar fluid flow past a continuously moving plate in the presence of magnetic field
Mansour M. A., Gorla R. S. R.
Applied Mechanics and Engineering
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1999
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Vol. 4, no 4
663-672
EN
A similarity analysis of the flow and heat transfer with magnetic field past a continuously moving semi-infinite permeable plate in a micropolar fluid is presented. The velocity, micro-rotation distribution, the temperature profiles, the skin friction and the rate of heat transfer are shown on graphs. Also the numerical values of the skin friction and the rate heat transfer are entered in tabular form.
12
MHD mixed convection boundary layer flow of a micropolar fluid from A horizontal cylinder
Mansour M. A., Gorla R. S. R.
Applied Mechanics and Engineering
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1999
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Vol. 4, no 4
649-662
EN
A boundary layer solution is presented to study the mixed convection from a horizontal cylinder embedded in electrically conducting micropolar fluid. The governing conservation equations have been solved numerically. Details of the velocity, microrotation and temperature fields are presented for various material parameters. Missing values of the velocity, angular velocity and thermal functions are tabulated.
13
Heat transfer from a stretching surface in a micropolar fluid
El-Hakiem M. A., Mohammadein A. A., Mansour M. A., Gorla R. S. R.
Applied Mechanics and Engineering
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1999
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Vol. 4, no 1
25-34
EN
The theory of micropolar fluids due to Eringen is used to formulate a set of boundary layer equations for the heat transfer from an arbitrarily stretching surface with non-uniform surface temperature. A two dimensional similarity solution to the governing momentum, angular momentum and energy equations is presented. The effects of the boundary conditions used for the microrotation term are discussed. Numerical data for the friction factor and Nusselt number has been shown graphically for a range of values of the material properties.
14
Thermal radiation effects on boundary layer flow on a continuous porous flat surface
Gorla R. S. R., Mansour M. A., El-Hawary H. M.
Applied Mechanics and Engineering
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1998
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Vol. 3, no 2
205-216
EN
An analysis is presented based upon the Chebyshev spectral method for the boundary-layer flow on a continuous porous flat surface. This technique reduces the problem to a system of nonlinear equations in the highest order derivatives which were solved by Newton's iterations.
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