scholarly journals Effect of Temperature-Dependent Variable Viscosity on Magnetohydrodynamic Natural Convection Flow along a Vertical Wavy Surface

2011 ◽  
Vol 2011 ◽  
pp. 1-10 ◽  
Author(s):  
Nazma Parveen ◽  
Md. Abdul Alim
Keyword(s):  
Heat Transfer ◽  
Natural Convection ◽  
Friction Coefficient ◽  
Skin Friction ◽  
Variable Viscosity ◽  
Skin Friction Coefficient ◽  
Effect Of Temperature ◽  
Convection Flow ◽  
Temperature Dependent ◽  
Natural Convection Flow

The effect of temperature dependent variable viscosity on magnetohydrodynamic (MHD) natural convection flow of viscous incompressible fluid along a uniformly heated vertical wavy surface has been investigated. The governing boundary layer equations are first transformed into a nondimensional form using suitable set of dimensionless variables. The resulting nonlinear system of partial differential equations are mapped into the domain of a vertical flat plate and then solved numerically employing the implicit finite difference method, known as Keller-box scheme. The numerical results of the surface shear stress in terms of skin friction coefficient and the rate of heat transfer in terms of local Nusselt number, the stream lines and the isotherms are shown graphically for a selection of parameters set consisting of viscosity parameter (), magnetic parameter (), and Prandtl number (Pr). Numerical results of the local skin friction coefficient and the rate of heat transfer for different values are also presented in tabular form.

Non-uniform mass transfer in MHD mixed convection flow of water over a sphere with variable viscosity and Prandtl number

2016 ◽  
Vol 26 (7) ◽  
pp. 2235-2251 ◽  
Author(s):  
J. Rajakumar ◽  
P. Saikrishnan ◽  
A. Chamkha
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Mixed Convection ◽  
Skin Friction ◽  
Variable Viscosity ◽  
Skin Friction Coefficient ◽  
Convection Flow ◽  
Mixed Convection Flow ◽  
Content Type ◽  
Slot Suction

Purpose The purpose of this paper is to consider axisymmetric mixed convection flow of water over a sphere with variable viscosity and Prandtl number and an applied magnetic field. Design/methodology/approach The non-similar solutions have been obtained from the origin of the streamwise co-ordinate to the point of zero skin friction using quasilinearization technique with an implicit finite-difference scheme. Findings The effect of M is not notable on the temperature and heat transfer coefficient when λ is large. The skin friction coefficient and velocity profile are enhance with the increase of MHD parameter M when λ is small. Viscous dissipation has no significant on the skin friction coefficient under MHD effect. For M=1, the movement of the slot or slot suction or slot injection do not cause any effect on flow separation. The slot suction and the movement of the slot in downstream direction delay the point of zero skin friction for M=0. Originality/value The present results are original and new for water boundary-layer flow over sphere in mixed convection flow with MHD effect and non-uniform mass transfer. So this study would be useful in analysing the skin friction and heat transfer coefficient on sphere of mixed convection flow of water boundary layer with MHD effect.

scholarly journals MHD natural convection flow with radiative heat transfer past an impulsively moving vertical plate with ramped temperature in the presence of hall current and thermal diffusion

2013 ◽  
Vol 18 (4) ◽  
pp. 1201-1220
Author(s):  
G.S. Seth ◽  
G.K. Mahato ◽  
S. Sarkar
Keyword(s):  
Heat Transfer ◽  
Natural Convection ◽  
Skin Friction ◽  
Radiative Heat Transfer ◽  
Vertical Plate ◽  
Radiative Heat ◽  
Hall Current ◽  
Convection Flow ◽  
Natural Convection Flow ◽  
Flow Parameters

Abstract An investigation on an unsteady MHD natural convection flow with radiative heat transfer of a viscous, incompressible, electrically conducting and optically thick fluid past an impulsively moving vertical plate with ramped temperature in a porous medium in the presence of a Hall current and thermal diffusion is carried out. An exact solution of momentum and energy equations, under Boussinesq and Rosseland approximations, is obtained in a closed form by the Laplace transform technique for both ramped temperature and isothermal plates. Expressions for the skin friction and Nusselt number for both ramped temperature and isothermal plates are also derived. The numerical values of fluid velocity and fluid temperature are displayed graphically versus the boundary layer coordinate y for various values of pertinent flow parameters for both ramped temperature and isothermal plates. The numerical values of the skin friction due to primary and secondary flows are presented in tabular form for various values of pertinent flow parameters.

scholarly journals Effect of Variable Viscosity on Natural Convection Flow Between Vertical Parallel Plates in the Presence of Heat Generation/Absorption

2019 ◽  
pp. 1-15
Author(s):  
Tada M. Kabir ◽  
Abiodun O. Ajibade
Keyword(s):  
Natural Convection ◽  
Skin Friction ◽  
Heat Generation ◽  
Variable Viscosity ◽  
Nonlinear Differential Equations ◽  
Convection Flow ◽  
Physical Parameters ◽  
Fluid Temperature ◽  
Parallel Plates ◽  
Natural Convection Flow

The present article was aimed at investigating the effects of variable viscosity on natural convection flow between vertical parallel plates in the presence of heat generation/absorption. The nonlinear differential equations governing the flow were solved using Homotopy perturbation method. The impacts of the several governing parameters on the velocity and temperature profiles are presented graphically and values of skin friction, rate of heat transfer, mass flux and mean temperature for various values of physical parameters are presented through tables. In the course of computation, it was revealed that viscosity  ontributes to decrease velocity and hence reduced resistance to flow. It was also discovered that as the heat generation increases, fluid temperature and velocity increase, while it decrease with the increase in heat absorption. Finally, it was concluded that the skin friction on both plates increase as viscosity increases.

Radiation effects on natural convection flow over an inclined flat plate with temperature-dependent viscosity

2010 ◽  
Vol 225 (2) ◽  
pp. 407-419 ◽  
Author(s):  
S Siddiqa ◽  
S Asghar ◽  
M A Hossain
Keyword(s):  
Natural Convection ◽  
Flat Plate ◽  
Variable Viscosity ◽  
Solution Technique ◽  
Convection Flow ◽  
Temperature Dependent ◽  
Natural Convection Flow ◽  
Temperature Dependent Viscosity ◽  
Local Skin ◽  
Dependent Viscosity

The effect of radiation on laminar natural convection flow of a viscous incompressible fluid over a semi-infinite flat plate inclined at a small angle to the horizontal with strong temperature-dependent viscosity has been investigated. The Rosseland approximation is considered while modelling the problem. The non-similar equations are obtained for upstream, downstream, and entire regimes, which are then solved numerically. For constant viscosity, the series solution technique has been employed in order to obtain solutions that are valid near the leading edge as well as in the downstream regime. Later, solutions of the governing equations have been obtained using the finite difference method along with the Keller box technique, taking into consideration variable viscosity. Effects of physical parameters like conduction—radiation para-meter Rd, surface temperature parameter θw, variable viscosity parameter λ, and Prandtl number Pr are shown on the local skin-friction coefficient Cf and the local Nusselt number, Nu. Effects of the parameters on the streamlines are also shown around the point of separation that occurs along the negatively inclined surface.

scholarly journals Joule heating and MHD free convection flow along a vertical wavy surface with viscosity and thermal conductivity dependent on temperature

2013 ◽  
Vol 10 (2) ◽  
pp. 81-98 ◽  
Author(s):  
Nazma Parveen ◽  
Md. Abdul Alim
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Friction Coefficient ◽  
Free Convection ◽  
Skin Friction ◽  
Joule Heating ◽  
Skin Friction Coefficient ◽  
Wavy Surface ◽  
Convection Flow ◽  
Free Convection Flow

A numerical study is conducted to analyze the effect of Joule heating and MHD (magnetohydrodynamic) free convection flow and heat transfer along a uniformly heated vertical wavy surface with temperature dependent variable viscosity and thermal conductivity. The governing boundary layer equations with associated boundary conditions for phenomenon are converted to non-dimensional form using the appropriate transformations. The resulting nonlinear system of partial differential equations are mapped into the domain of a vertical flat plate and solved numerically by employing implicit finite difference method, known as the Keller-box scheme. The behavior of the fluid in the ranges of Joule heating parameter (0.0–2.0), viscosity parameter (0.0–20.0) and thermal conductivity parameter (0.0 –10.0) are explained in details. It is found that the flow and temperature fields are strongly dependent on the above stated parameters for the ranges considered. The skin friction coefficient and the rate of heat transfer are also presented. The skin friction coefficient and the heat transfer for different values of Prandtl number Pr are compared with previously published work and are found to be in excellent agreement.DOI: http://dx.doi.org/10.3329/jname.v10i2.11707

scholarly journals MHD NATURAL CONVECTION FLOW ALONG A VERTICAL WAVY SURFACE IN PRESENCE OF HEAT GENERATION/ABSORPTION WITH VISCOSITY DEPENDENT ON TEMPERATURE

2013 ◽  
Vol 42 (1) ◽  
pp. 47-55
Author(s):  
N. Parveen ◽  
M. A. Alim
Keyword(s):  
Heat Transfer ◽  
Natural Convection ◽  
Heat Generation ◽  
Variable Viscosity ◽  
Wavy Surface ◽  
Convection Flow ◽  
Heat Transfer Characteristics ◽  
Natural Convection Flow ◽  
Box Scheme ◽  
Vertical Flat Plate

The present numerical simulation is analyzed the Magnetohydrodynamic natural convection flow andheat transfer along a uniformly heated vertical wavy surface in presence of heat generation/absorption withtemperature dependent variable viscosity. Using the appropriate transformations the governing boundary layerequations are reduced to non-dimensional forms. The resulting nonlinear system of partial differentialequations are mapped into the domain of a vertical flat plate and then solved numerically applying implicitfinite difference method together with Keller-box scheme. The solutions are expressed in terms of the skinfriction coefficient, the rate of heat transfer, the streamlines as well as the isotherms over the whole boundarylayer. The implications of heat generation/absorption parameter (Q) and viscosity parameter (?) on the flowstructure and heat transfer characteristics are investigated in detail while, Prandtl number (Pr), magneticparameter (M) and the amplitude-to-length ratio of the wavy surface (?) are considered fixed. Comparison withpreviously published work is performed and is found to be in good agreement.DOI: http://dx.doi.org/10.3329/jme.v42i1.15944

scholarly journals Unsteady/Steady Natural Convection Flow of Reactive Viscous Fluid in a Vertical Annulus

2013 ◽  
Vol 18 (1) ◽  
pp. 73-83 ◽  
Author(s):  
B.K. Jha ◽  
A.K. Samaila ◽  
A.O. Ajibade
Keyword(s):  
Heat Transfer ◽  
Steady State ◽  
Natural Convection ◽  
Differential Equations ◽  
Viscous Fluid ◽  
Skin Friction ◽  
Convection Flow ◽  
Natural Convection Flow ◽  
Vertical Annulus ◽  
Analytical Expressions

This paper presents both analytical and numerical analyses of a fully developed unsteady/steady natural convection flow of a reactive viscous fluid in an open ended vertical annulus. Analytical expressions for velocity, temperature, skin-friction and rate of heat transfer are obtained after simplifying and solving the governing differential equations with reasonable approximations. The interesting result found in this study is that an increase in non-dimensional time (t) , increases both temperature and velocity profiles until a steady-state value is attained. Subsequent results obtained by numerical calculations show excellent agreement with analytical results.

scholarly journals Conjugate effects of temperature sensitive viscosity and thermal conductivity on free convection flow along a wavy surface with heat generation

2013 ◽  
Vol 10 (2) ◽  
pp. 139-148 ◽  
Author(s):  
Md. Abdul Alim ◽  
M. Miraj Akand ◽  
M. Rezaul Karim
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Friction Coefficient ◽  
Skin Friction ◽  
Heat Generation ◽  
Skin Friction Coefficient ◽  
Numerical Results ◽  
Wavy Surface ◽  
Convection Flow ◽  
Surface Shear Stress

The effects of internal heat generation on natural convection flow with temperature dependent variable viscosity along a uniformly heated vertical wavy surface have been investigated. The governing boundary layer equations are first transformed into a non-dimensional form using suitable set of dimensionless variables. The resulting nonlinear system of partial differential equations are mapped into the domain of a vertical flat plate and then solved numerically employing the implicit finite difference method, known as Keller-box scheme. Numerical results of the surface shear stress in terms of skin friction coefficient and the rate of heat transfer in terms of local Nusselt number, the stream lines as well as the isotherms are shown graphically for a selection of parameters set consisting of viscosity variation parameter e, thermal conductivity parameter g, heat generation parameter Q and Prandtl number Pr. Numerical results of the local skin friction coefficient and the rate of heat transfer for different values are presented in tabular form and graphically.DOI: http://dx.doi.org/10.3329/jname.v10i2.9450

scholarly journals MHD natural convection flow of Casson fluid in an annular microchannel containing porous medium with heat generation/absorption

2020 ◽  
Vol 9 (1) ◽  
pp. 223-232 ◽  
Author(s):  
B.J. Gireesha ◽  
S. Sindhu
Keyword(s):  
Porous Medium ◽  
Natural Convection ◽  
Skin Friction ◽  
Interaction Parameter ◽  
Heat Generation ◽  
Velocity Slip ◽  
Casson Fluid ◽  
Convection Flow ◽  
Natural Convection Flow ◽  
Wall Interaction

AbstractThis study has been conducted to focus on natural convection flow of Casson fluid through an annular microchannel formed by two cylinders in the presence of magnetic field. The process of heat generation/absorption is taken into consideration. Combined effects of various parameters such as porous medium, velocity slip and temperature jump are considered. Solution of the present mathematical model is obtained numerically using fourth-fifth order Runge-Kutta-Fehlberg method. The flow velocity, thermal field, skin friction and Nusselt number are scrutinized with respect to the involved parameters of interest such as fluid wall interaction parameter, rarefaction parameter, Casson parameter and Darcy number with the aid of graphs. It is established that higher values of Casson parameter increases the skin friction coefficient. Further it is obtained that rate of heat transfer diminishes as fluid wall interaction parameter increases.

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