scholarly journals Two dominant analytical methods for thermal analysis of convective step fin with variable thermal conductivity

2014 ◽  
Vol 18 (2) ◽  
pp. 431-442 ◽  
Author(s):  
Mohsen Torabi ◽  
Hessameddin Yaghoobi
Keyword(s):  
Thermal Conductivity ◽  
Homotopy Perturbation Method ◽  
Variational Iteration Method ◽  
Transformation Method ◽  
Variable Thermal Conductivity ◽  
Step Change ◽  
Homotopy Perturbation ◽  
Thermal Conductivity Parameter ◽  
Conductivity Parameter ◽  
Accurate Numerical Solution

Heat transfer in a straight fin with a step change in thickness and variable thermal conductivity which is losing heat by convection to its surroundings is developed via differential transformation method (DTM) and variational iteration method (VIM). In this study, we compare DTM and VIM results, with those of homotopy perturbation method (HPM) and an accurate numerical solution to verify the accuracy of the proposed methods. As an important result, it is depicted that the DTM results are more accurate in comparison with those obtained by VIM and HPM. After these verifications the effects of parameters such as thickness ratio, ?, dimensionless fin semi thickness,?, length ratio, ?, thermal conductivity parameter, ?, Biot number, Bi, on the temperature distribution are illustrated and explained.

scholarly journals Determination of temperature distribution for annular fins with temperature dependent thermal conductivity by HPM

2011 ◽  
Vol 15 (suppl. 1) ◽  
pp. 111-115 ◽  
Author(s):  
Domiri Ganji ◽  
Ziabkhsh Ganji ◽  
Domiri Ganji
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Temperature Distribution ◽  
Perturbation Method ◽  
Homotopy Perturbation Method ◽  
Variable Thermal Conductivity ◽  
Temperature Dependent ◽  
Homotopy Perturbation ◽  
Annular Fin ◽  
Temperature Dependent Thermal Conductivity

In this paper, homotopy perturbation method has been used to evaluate the temperature distribution of annular fin with temperature-dependent thermal conductivity and to determine the temperature distribution within the fin. This method is useful and practical for solving the nonlinear heat transfer equation, which is associated with variable thermal conductivity condition. The homotopy perturbation method provides an approximate analytical solution in the form of an infinite power series. The annular fin heat transfer rate with temperature-dependent thermal conductivity has been obtained as a function of thermo-geometric fin parameter and the thermal conductivity parameter describing the variation of the thermal conductivity

Flow and Heat Transfer of Powell–Eyring Fluid due to an Exponential Stretching Sheet with Heat Flux and Variable Thermal Conductivity

2015 ◽  
Vol 70 (3) ◽  
pp. 163-169 ◽  
Author(s):  
Ahmed M. Megahed
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Heat Flux ◽  
Differential Equations ◽  
Variable Thermal Conductivity ◽  
Physical Parameters ◽  
Flow And Heat Transfer ◽  
Non Linear ◽  
Thermal Conductivity Parameter ◽  
Conductivity Parameter

AbstractAn analysis was carried out to describe the problem of flow and heat transfer of Powell–Eyring fluid in boundary layers on an exponentially stretching continuous permeable surface with an exponential temperature distribution in the presence of heat flux and variable thermal conductivity. The governing partial differential equations describing the problem were transformed into a set of coupled non-linear ordinary differential equations and then solved with a numerical technique using appropriate boundary conditions for various physical parameters. The numerical solution for the governing non-linear boundary value problem is based on applying the shooting method over the entire range of physical parameters. The effects of various parameters like the thermal conductivity parameter, suction parameter, dimensionless Powell–Eyring parameters and the Prandtl number on the flow and temperature profiles as well as on the local skin-friction coefficient and the local Nusselt number are presented and discussed. In this work, special attention was given to investigate the effect of the thermal conductivity parameter on the velocity and temperature fields above the sheet in the presence of heat flux. The numerical results were also validated with results from a previously published work on various special cases of the problem, and good agreements were seen.

scholarly journals Electrically Conducting Flow through Exponential Power Law Fluid with Variable Thermal Conductivity

2019 ◽  
Vol 24 (3) ◽  
pp. 539-548
Author(s):  
M. Ferdows ◽  
M.Z.I. Bangalee ◽  
D. Liu
Keyword(s):  
Magnetic Field ◽  
Heat Transfer ◽  
Thermal Conductivity ◽  
Variable Thermal Conductivity ◽  
Skin Friction Coefficient ◽  
Momentum Equation ◽  
Electrically Conducting ◽  
Thermal Conductivity Parameter ◽  
Conductivity Parameter ◽  
Exponential Power

Abstract The problem of exponential law of steady, incompressible fluid flow in boundary layer and heat transfer are studied in an electrically conducting fluid over a semi-infinite vertical plate assuming the variable thermal conductivity in the presence of a uniform magnetic field. The governing system of equations including the continuity equation, momentum equation and energy equation have been transformed into nonlinear coupled ordinary differential equations using appropriate similarity variables. All the numerical and graphical solutions are obtained through the use of Maple software. The solutions are found to be dependent on three dimensionless parameters including the magnetic field parameter M, thermal conductivity parameter β and Prandtl number Pr. Representative velocity and temperature profiles are presented at various values of the governing parameters. The skin-friction coefficient and the rate of heat transfer are also calculated for different values of the parameters.

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 A Comparative Analysis of Fractional-Order Gas Dynamics Equations via Analytical Techniques

Mathematics ◽  
2021 ◽  
Vol 9 (15) ◽  
pp. 1735
Author(s):  
Shuang-Shuang Zhou ◽  
Nehad Ali Shah ◽  
Ioannis Dassios ◽  
S. Saleem ◽  
Kamsing Nonlaopon
Keyword(s):  
Homotopy Perturbation Method ◽  
Graphical Representation ◽  
Analytical Techniques ◽  
Variational Iteration Method ◽  
Computational Techniques ◽  
System Of Nonlinear Equations ◽  
Gas Dynamics Equations ◽  
Homotopy Perturbation ◽  
Fractional System ◽  
Modified Forms

This article introduces two well-known computational techniques for solving the time-fractional system of nonlinear equations of unsteady flow of a polytropic gas. The methods suggested are the modified forms of the variational iteration method and the homotopy perturbation method by the Elzaki transformation. Furthermore, an illustrative scheme is introduced to verify the accuracy of the available techniques. A graphical representation of the exact and derived results is presented to show the reliability of the suggested approaches. It is also shown that the findings of the current methodology are in close harmony with the exact solutions. The comparative solution analysis via graphs also represents the higher reliability and accuracy of the current techniques.

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