scholarly journals Effects of pressure work on natural convection flow around a sphere with radiation heat loss

2010 ◽  
Vol 15 (3) ◽  
pp. 287-298
Author(s):  
T. Akhter ◽  
M. A. Alim
Keyword(s):  
Natural Convection ◽  
Heat Loss ◽  
Nonlinear Partial Differential Equations ◽  
Convection Flow ◽  
Radiation Heat ◽  
Natural Convection Flow ◽  
Local Skin ◽  
Pressure Work ◽  
Boundary Layer Equations ◽  
Radiation Heat Loss

The effects of pressure work with radiation heat loss on natural convection flow on a sphere have been investigated in this paper. The governing boundary layer equations are first transformed into a non-dimensional form and the resulting nonlinear partial differential equations are then solved numerically using finite-difference method with Keller-box scheme. We have focused our attention on the evaluation of shear stress in terms of local skin friction and rate of heat transfer in terms of local Nusselt number, velocity as well as temperature profiles. Numerical results have been shown graphically and tabular form for some selected values of parameters set consisting of radiation parameter Rd, pressure work parameter Ge, surface temperature parameter θw and the Prandtl number Pr.

scholarly journals Conjugate Effects of Heat and Mass Transfer on Natural Convection Flow Across an Isothermal Horizontal Circular Cylinder With Chemical Reaction

2007 ◽  
Vol 12 (2) ◽  
pp. 191-201 ◽  
Author(s):  
Md. A. Hye ◽  
Md. M. Molla ◽  
M. A. H. Khan
Keyword(s):  
Boundary Layer ◽  
Natural Convection ◽  
Chemical Reaction ◽  
Transfer Rate ◽  
Convection Flow ◽  
Natural Convection Flow ◽  
Species Concentration ◽  
Local Skin ◽  
Boundary Layer Equations ◽  
Wide Range

Natural convection flow across an isothermal cylinder immersed in a viscous incompressible fluid in the presence of species concentration and chemical reaction has been investigated. The governing boundary layer equations are transformed into a system of non-dimensional equations and the resulting nonlinear system of partial differential equations is reduced to a system of local non-similarity boundary layer equations, which is solved numerically by a very efficient implicit finite difference method together with the Keller-box scheme. Numerical results are presented by the velocity, temperature and species concentration profiles of the fluid as well as the local skin-friction coefficient, local heat transfer rate and local species concentration transfer rate for a wide range of chemical reaction parameter γ (γ = 0.0, 0.5, 1.0, 2.0, 4.0), buoyancy ratio parameter N (N = −1.0, −0.5, 0.0, 0.5, 1.0), Schmidt number Sc (Sc = 0.7, 10.0, 50.0, 100.0) andPrandtl number Pr (Pr = 0.7, 7.0).

Magnetohydrodynamic Natural Convection Flow on a Sphere in Presence of Heat Generation

2005 ◽  
Vol 10 (4) ◽  
pp. 349-363 ◽  
Author(s):  
Md. M. Molla ◽  
M. A. Taher ◽  
Md. M. K. Chowdhury ◽  
Md. A. Hossain
Keyword(s):  
Natural Convection ◽  
Heat Generation ◽  
Numerical Solutions ◽  
Convection Flow ◽  
Surface Shear Stress ◽  
Natural Convection Flow ◽  
Surface Shear ◽  
Local Skin ◽  
Boundary Layer Equations ◽  
Keller Box Method

The present work describes the effect of magnetohydrodynamic natural convection flow on a sphere in presence of heat generation. The governing boundary layer equations are first transformed into a non-dimensional form and the resulting nonlinear system of partial differential equations arethen solved numerically using the Keller-box method. Here we have focused our attention on the evolution of the surface shear stress in terms of local skin friction and the rate of heat transfer in terms of local Nusselt number, velocity distribution as well as temperature distribution for a selection of parameter sets consisting of heat generation parameter Q (= 0.0, 0.5, 1.0, 2.0) and the magnetic parameter M (= 0.0, 0.2, 0.5, 0.8, 1.0). Numerical solutions have been considered for Prandtl number Pr (= 0.7, 1.0, 2.0).

scholarly journals Viscous Dissipation Effects on MHD Natural Convection Flow along a Sphere

1970 ◽  
Vol 36 ◽  
pp. 44-48 ◽  
Author(s):  
Md. M Alam ◽  
MA Alim ◽  
Md. MK Chowdhury
Keyword(s):  
Nusselt Number ◽  
Natural Convection ◽  
Viscous Dissipation ◽  
Convection Flow ◽  
Natural Convection Flow ◽  
Local Skin ◽  
Boundary Layer Equations ◽  
Box Scheme ◽  
Dissipation Parameter ◽  
Local Skin Friction

In this paper, we describe the viscous dissipation effects in magnetohydrodynamic (MHD) natural convection flow on a sphere. The natural convection laminar flow from a sphere immersed in a viscous incompressible optically thin fluid in the presence of magnetic field has been investigated. The governing boundary layer equations are first transformed into a non-dimensional form and the resulting nonlinear system of partial differential equations are then solved numerically using a very efficient finite-difference method with Keller-box scheme. Here we have focused our attention on the evolution of shear stress in terms of the local skin friction and the rate of heat transfer in terms of local Nusselt number, velocity profiles as well as temperature profiles for some selected parameters consisting of magnetic parameter M, viscous dissipation parameter N and the Prandlt number Pr.Keywords: Viscous dissipation, magnetohydrodynamics, natural convection, Nusselt number. Journal of Mechanical Engineering Vol.36 Dec. 2006 pp.44DOI = 10.3329/jme.v36i0.810

scholarly journals Joule heating effect on magnetohydrodynamic natural convection flow along a vertical wavy surface

2012 ◽  
Vol 9 (1) ◽  
pp. 11-24 ◽  
Author(s):  
Nazma Parveen ◽  
M A Alim
Keyword(s):  
Natural Convection ◽  
Joule Heating ◽  
Skin Friction Coefficient ◽  
Wavy Surface ◽  
Convection Flow ◽  
Surface Shear Stress ◽  
Natural Convection Flow ◽  
Surface Shear ◽  
Boundary Layer Equations ◽  
Marine Engineering

In this paper, the effect of Joule heating on magnetohydrodynamic natural convection flow of viscous incompressible fluid along a uniformly heated vertical wavy surface has been investigated. The governing boundary layer equations with associated boundary conditions for this phenomenon are converted to nondimensional form using a suitable transformation. The equations are mapped into the domain of a vertical flat plate and then solved numerically employing the implicit finite difference method, known as the Keller-box scheme. Effects of pertinent parameters, such as the Joule heating parameter (J), Prandtl number (Pr), magnetic parameter (M) and the amplitude of the wavy surface ? on the surface shear stress in terms of the skin friction coefficient (Cfx), the rate of heat transfer in terms of local Nusselt number (Nux), the streamlines and the isotherms are discussed. A comparison with previously published work is performed and the results show excellent agreement. DOI: http://dx.doi.org/10.3329/jname.v9i1.5954 Journal of Naval Architecture and Marine Engineering 9(2012) 11-24

scholarly journals Viscous Dissipation Effects on MHD Natural Convection Flow Over a Sphere in the Presence of Heat Generation

2007 ◽  
Vol 12 (4) ◽  
pp. 447-459 ◽  
Author(s):  
Md. M. Alam ◽  
M. A. Alim ◽  
Md. M. K. Chowdhury
Keyword(s):  
Natural Convection ◽  
Viscous Dissipation ◽  
Heat Generation ◽  
Skin Friction Coefficient ◽  
Convection Flow ◽  
Surface Shear Stress ◽  
Natural Convection Flow ◽  
Surface Shear ◽  
Boundary Layer Equations ◽  
Box Scheme

In this paper, the viscous dissipation effects on magnetohydrodynamic natural convection flow over a sphere in the presence of heat generation have been described. The governing boundary layer equations are first transformed into a nondimensional form and the resulting nonlinear system of partial differential equations are then solved numerically using finite-difference method together with 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, velocity as well as temperature profiles are shown graphically and tabular form for a selection of parameters set consisting of heat generation parameter Q, magnetic parameter M, viscous dissipation parameter N and the Prandlt number Pr.

Natural convection flow of a non-Newtonian power-law fluid from a slotted vertical surface with uniform surface heat flux

2008 ◽  
Vol 223 (3) ◽  
pp. 637-642 ◽  
Author(s):  
R S R Gorla ◽  
M A Hossain
Keyword(s):  
Heat Transfer ◽  
Natural Convection ◽  
Power Law ◽  
Vertical Surface ◽  
Surface Heat ◽  
Convection Flow ◽  
Natural Convection Flow ◽  
Boundary Layer Equations ◽  
Power Law Index ◽  
Type Power

In the present paper, the natural convection flow of an Ostwalde—de Waele type power-law non-Newtonian fluid past a uniformly heated vertical slotted surface has been investigated numerically. The equations governing the flow and heat transfer are reduced to local non-similarity form. The transformed boundary-layer equations are solved numerically using implicit finite-difference method for values of ξ in the interval [0, ∞]. Solutions for heat transfer rate obtained for the rigid surface compared well with those documented in the published literature. From the present analysis, it is observed that an increase in ξ leads to increasing the skin-friction as well as reduction in heat transfer at the surface. As the power-law index n increases, the friction factor as well as the surface heat transfer increases.

Effects of Viscous Dissipation and Joule Heating on Natural Convection Flow of a Viscous Fluid from Heated Vertical Wavy Surface

2011 ◽  
Vol 66 (6-7) ◽  
pp. 427-440 ◽  
Author(s):  
Nasser S. Elgazery ◽  
Nader Y. Abd Elazem
Keyword(s):  
Nusselt Number ◽  
Natural Convection ◽  
Skin Friction ◽  
Viscous Dissipation ◽  
Joule Heating ◽  
Wavy Surface ◽  
Convection Flow ◽  
Natural Convection Flow ◽  
Local Skin ◽  
Local Skin Friction

A mathematical model will be analyzed in order to study the effects of viscous dissipation and Ohmic heating (Joule heating) on magnetohydrodynamic (MHD) natural convection flow of a temperature dependent viscosity from heated vertical wavy surface. The present physical problem is studied numerically by using the appropriate variables, which reduce the complex wavy surface into a flat one. An implicit marching Chebyshev collocation scheme is employed for the analysis. Numerical solutions are obtained for velocity, temperature, local skin friction, and Nusselt number for a selection of parameter sets consisting of Eckert number, Prandtl number, MHD variation, and amplitude-wavelength ratio parameter. Numerical results show that these parameters have significant influences on the velocity and the temperature profiles as well as for the local skin friction and Nusselt number

scholarly journals Electrical Unsteady MHD Natural Convection Flow of Nanofluid with Thermal Stratification and Heat Generation/Absorption

MATEMATIKA ◽  
2018 ◽  
Vol 34 (2) ◽  
pp. 393-417 ◽  
Author(s):  
Yahaya Shagaiya Daniel ◽  
Abdul Aziz Zainal ◽  
Zuhaila Ismail ◽  
Faisal Salah
Keyword(s):  
Natural Convection ◽  
Differential Equations ◽  
Thermal Radiation ◽  
Heat Generation ◽  
Thermal Stratification ◽  
Nonlinear Partial Differential Equations ◽  
Convection Flow ◽  
Natural Convection Flow ◽  
Reaction Heat ◽  
Radiation Chemical

In this paper, we analyzed the effects of thermal radiation, chemical reaction, heat generation/absorption, magnetic and electric fields on unsteady natural convection flow and heat transfer due to nanofluid over a permeable stretching sheet. The transport equations used passively controlled boundary condition rather than actively. A similarity solution is employed to transformed the governing equations from nonlinear partial differential equations to a set of ordinary differential equations, and then solve using Keller box method. It was found that the temperature is a decreasing function with the thermal stratification due to the fact the density of the fluid in the lower vicinity is much higher compared to the upper region, whereas the thermal radiation, viscous dissipation and heat generation enhanced the nanofluid temperature and thermal layer thickness.

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