scholarly journals MHD-Conjugate Free Convection from an Isothermal Horizontal Circular Cylinder with Joule Heating and Heat Generation

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
NHM. A. Azim ◽  
M. K. Chowdhury
Keyword(s):  
Heat Transfer ◽  
Circular Cylinder ◽  
Skin Friction ◽  
Heat Generation ◽  
Joule Heating ◽  
Numerical Study ◽  
Internal Heat ◽  
Governing Equations ◽  
Generation Parameter ◽  
Horizontal Circular Cylinder

The present work is devoted to the numerical study of laminar magnetohydrodynamic (MHD) conjugate natural convection flow from a horizontal circular cylinder taking into account Joule heating and internal heat generation. The governing equations and the associated boundary conditions for this analysis are made nondimensional forms using a set of dimensionless variables. Thus, the nondimensional governing equations are solved numerically using finite difference method with Keller box scheme. Numerical outcomes are found for different values of the magnetic parameter, conjugate conduction parameter, Prandtl number, Joule heating parameter, and heat generation parameter for the velocity and the temperature within the boundary layer as well as the skin friction coefficients and the rate of heat transfer along the surface. It is found that the skin friction increases, and heat transfer rate decreases for escalating value of Joule heating parameter and heat generation parameter. Results are presented graphically with detailed discussion.

Numerical Investigation of Forced Convective Heat Transfer Around and Through a Porous Circular Cylinder With Internal Heat Generation

2012 ◽  
Vol 134 (6) ◽  
Author(s):  
Mohammad Sadegh Valipour ◽  
Ariyan Zare Ghadi
Keyword(s):  
Heat Transfer ◽  
Circular Cylinder ◽  
Convective Heat Transfer ◽  
Convective Heat ◽  
Heat Generation ◽  
Internal Heat ◽  
Internal Heat Generation ◽  
Staggered Grid ◽  
Polar Coordinate System ◽  
Governing Equations

In this study, convective heat transfer around and through a porous circular cylinder together with internal heat generation has been investigated numerically. Governing equations containing continuity, momentum, and energy equations have been developed in polar coordinate system in both porous and nonporous media based on single-domain approach. However, governing equations in porous medium are derived using intrinsic volume averaging method. The equations are solved numerically based on finite volume method over staggered grid arrangement. Also, pressure correction-based iterative algorithm, SIMPLE, is applied for solving the pressure linked equations. Reynolds and Peclet numbers (based on cylinder diameter and velocity of free stream) are from 1 to 40. Also, Darcy number (Da) varies within the range of 10-6≤Da≤10-2 and porosity is considered 0.9 for all calculations. The influence of Da and Re numbers on local and average Nu numbers has been investigated. It is found that the local and average Nu numbers increase with any increase in Da number. Two correlations of average Nu number are presented for high and low Da numbers.

scholarly journals Analysis of the Physical Behavior of the Periodic Mixed-Convection Flow around a Nonconducting Horizontal Circular Cylinder Embedded in a Porous Medium

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Muhammad Ashraf ◽  
Zia Ullah ◽  
Saqib Zia ◽  
Sayer O. Alharbi ◽  
Dumitru Baleanu ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Porous Medium ◽  
Fluid Flow ◽  
Partial Differential Equations ◽  
Circular Cylinder ◽  
Differential Equations ◽  
Mixed Convection ◽  
Skin Friction ◽  
Current Density ◽  
Horizontal Circular Cylinder

An oscillatory mixed-convection fluid flow mechanism across a nonconducting horizontal circular cylinder embedded in a porous medium has been computed. For this purpose, a model in the form of partial differential equations is formulated, and then, the governing equations of the dimensionless model are transformed into the primitive form for integration by using primitive variable formulation. The impact of emerging parameters such as porous medium parameter Ω , Richardson number λ , magnetic force parameter ξ , and Prandtl number Pr on skin friction, heat transfer, and current density is interpreted graphically. It is demonstrated that accurate numerical results can be obtained by the present method by treating nonoscillating and oscillating parts of coupled partial differential equations simultaneously. In this study, it is well established that the transient convective heat transfer, skin friction, and current density depend on amplitude and phase angle. One of the objects of the present study is to predict the mechanism of heat and fluid flow around different angles of a nonconducting horizontal circular cylinder embedded in a porous medium.

scholarly journals Effect of Variable Thermal Conductivity on Buoyant Convection in a Cavity with Internal Heat Generation

2007 ◽  
Vol 12 (1) ◽  
pp. 113-122 ◽  
Author(s):  
S. Sivasankaran
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Numerical Study ◽  
Internal Heat ◽  
Variable Thermal Conductivity ◽  
Governing Equations ◽  
Heat Transfer Characteristics ◽  
Square Cavity ◽  
Thermal Conductivity Parameter ◽  
Conductivity Parameter

A numerical study has been made to analyze the effects of variable thermal conductivity on the natural convection of heat generating fluids contained in a square cavity with isothermal walls and the top and bottom perfectly insulated surfaces. The flow is assumed to be two-dimensional. Calculations are carried out by solving governing equations for different parameters. The flow pattern and the heat transfer characteristics inside the cavity are presented in the form of steady-state streamlines, isotherms and velocity profiles. The heat transfer rate is increased by an increase in the thermal conductivity parameter.

scholarly journals Mixed Convection Flow Of Viscoelastic Nanofluid Past A Horizontal Circular Cylinder In Presence Of Heat Generation

2020 ◽  
Vol 16 (2) ◽  
pp. 166-172
Author(s):  
Rahimah Mahat ◽  
Noraihan Afiqah Rawi ◽  
Abdul Rahman Mohd Kasim ◽  
Sharidan Shafie
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Heat Generation ◽  
Volume Fraction ◽  
Viscoelastic Nanofluid ◽  
Nanoparticles Volume Fraction ◽  
Generation Parameter ◽  
Horizontal Circular Cylinder

The steady two-dimensional mixed convection boundary layer flow of viscoelastic nanofluid past a horizontal circular cylinder with convective boundary condition in presence of heat generation has been studied numerically. Carboxymethyl cellulose solution (CMC) is chosen as the base fluid and copper as a nanoparticle with the Prandtl number Pr = 6.2. The Tiwari and Das model has been considered in this study. The governing partial differential equations are reduced to a system of ordinary differential equations by introducing similarity transformations. The nonlinear similarity equations are solved numerically by applying the Keller-box method. The numerical results are presented graphically for different values of the parameters including the heat generation parameter, nanoparticles volume fraction, and Biot number. A systematic study is discussed to analyze the effect of these parameters on the velocity and temperature profiles as well as the skin friction and heat transfer coefficient. The thermal boundary layer shows the changes in variation behavior when the nanoparticles volume fraction, heat generation and Biot number are increased. Heat transfer coefficient is increasing function of heat generation parameter. Nanoparticles volume fraction on heat transfer coefficient have opposite effect when compared with heat generation parameter.

Radiation and heat generation effects on viscous Joule heating MHD-conjugate heat transfer for a vertical flat plate

2014 ◽  
Vol 92 (6) ◽  
pp. 509-521 ◽  
Author(s):  
M.M. Ali ◽  
A.A. Mamun ◽  
M.A. Maleque
Keyword(s):  
Heat Transfer ◽  
Flat Plate ◽  
Heat Generation ◽  
Joule Heating ◽  
Conjugate Heat Transfer ◽  
Coupling Effect ◽  
Flow Characteristics ◽  
Internal Heat ◽  
Skin Friction Coefficient ◽  
Convection Flow

Conjugate heat transfer formed by the coupling effect of conduction inside and free convection flow along the flat plate is analyzed. The Joule heating effect because of considered magnetohydrodynamics (MHD) along with viscous dissipation, heat generation, and radiation phenomena are included in the investigation. The converted dimensionless partial differential equations representing the aforementioned flow characteristics are transformed into nonlinear equations with the help of a stream function with similarity variable. Finally, a numerical solution is carried out using the implicit finite difference method to analyze the flow behaviors in terms of velocity, temperature, skin friction coefficient, heat transfer rate, and surface temperature. A complete parametric analysis is done on the numerical results to show the effects of the radiation parameter, magnetic parameter, Eckert number, heat generation parameter, conjugate conduction parameter, and Prandtl number. It is found that thermal radiation, viscous Joule heating, and internal heat generation in the presence of axial conduction effects have a significant effect on MHD natural convection flow and thermal fields.

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