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.

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 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.

Convective heat transfer past a continuously moving plate embedded in a non-Darcian porous medium in the presence of a magnetic field

2001 ◽  
Vol 79 (7) ◽  
pp. 1031-1038 ◽  
Author(s):  
E M Abo-Eldahab ◽  
M S El Gendy
Keyword(s):  
Magnetic Field ◽  
Heat Transfer ◽  
Stretching Sheet ◽  
Skin Friction Coefficient ◽  
Moving Plate ◽  
Convection And Heat Transfer ◽  
Electrically Conducting ◽  
Boundary Layer Equations ◽  
Convective Parameter ◽  
Inertia Parameter

In the present study, free-convection and heat-transfer behavior of an electrically conducting fluid is investigated near a stretching sheet embedded in a non-Darcian medium. The temperature of the stretching sheet is varied. The sheet is stretched linearly with variable velocity and temperature. Boundary-layer equations are derived. The resulting approximate nonlinear ordinary differential equations are solved numerically. Velocity and temperature profiles as well as the local Nusselt number and skin-friction coefficient are computed for various values of the magnetic field, the Prandtl number, the free convective parameter, and the inertia parameter. PACS No.: 44.30+v

Entropy generation analysis for peristalsis of magneto Jeffrey materials

2021 ◽  
pp. 095440892110412
Author(s):  
Tasawar Hayat ◽  
Farhat Bibi ◽  
Ambreen Afsar Khan ◽  
Akbar Zaman ◽  
Ahmed Alsaedi
Keyword(s):  
Magnetic Field ◽  
Thermal Conductivity ◽  
Entropy Generation ◽  
Thermal Conductivity Coefficient ◽  
Temperature Dependent ◽  
Thermal Fields ◽  
Thermal Conductivity Parameter ◽  
Conductivity Parameter ◽  
Temperature Dependent Thermal Conductivity ◽  
Heat Transfer Parameter

This article communicates peristalsis of Jeffrey material in curved geometry. Here, material has temperature-dependent thermal conductivity and viscosity. Mathematical modeling of an inclined magnetic field in curved configuration has been presented in this article. Irreversibility effects have been analyzed through entropy generation. Slip conditions are entertained both for velocity and thermal fields. Problem is first reduced in wave frame and then lubrication approach has been utilized. Numerical solution of dimensionless problem is obtained and important parameters of curiosity are examined. It is noticed that velocity enhances for higher viscosity whereas temperature decreases for higher thermal conductivity coefficient. Velocity of the flow is maximum for inclination of magnetic field to be zero and it is minimum for [Formula: see text] Heat transfer parameter enhances both for thermal conductivity parameter and Hartmann number. Temperature is high for curved configuration when compared with straight channel. It is observed that entropy remains unchanged in center of the channel and it is maximum near the channel walls. Entropy generation decays near the channel walls by higher viscosity and thermal conductivity parameters. However, entropy is more for higher inclination of magnetic field.

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.

Magnetohydrodynamic flow of nano Williamson fluid generated by stretching plate with multiple slips

2019 ◽  
Vol 15 (5) ◽  
pp. 871-894 ◽  
Author(s):  
Jawad Raza ◽  
Fateh Mebarek-Oudina ◽  
B. Mahanthesh
Keyword(s):  
Thermal Conductivity ◽  
Differential Equations ◽  
Regression Line ◽  
Skin Friction Coefficient ◽  
Content Type ◽  
Williamson Fluid ◽  
Thermal Conductivity Parameter ◽  
Conductivity Parameter ◽  
Stretching Plate ◽  
Multiple Slips

Purpose The purpose of this paper is to present an exploration of multiple slips and temperature dependent thermal conductivity effects on the flow of nano Williamson fluid over a slendering stretching plate in the presence of Joule and viscous heating aspects. The effectiveness of nanoparticles is deliberated by considering Brownian moment and thermophoresis slip mechanisms. The effects of magnetism and radiative heat are also deployed. Design/methodology/approach The governing partial differential equations are non-dimensionalized and reduced to multi-degree ordinary differential equations via suitable similarity variables. The subsequent non-linear problem treated for numerical results. To measure the amount of increase/decrease in skin friction coefficient, Nusselt number and Sherwood number, the slope of linear regression line through the data points are calculated. Statistical approach is implemented to analyze the heat transfer rate. Findings The results show that temperature distribution across the flow decreases with thermal conductivity parameter. The maximum friction factor is ascertained at stronger magnetic field. Originality/value In the current paper, the magneto-nano Williamson fluid flow inspired by a stretching sheet of variable thickness is examined numerically. The rationale of the present study is to generalize the studies of Mebarek-Oudina and Makinde (2018) and Williamson (1929).

Analysis of a Convective-Radiative Continuously Moving Fin with Temperature-Dependent Thermal Conductivity

2020 ◽  
Vol 21 (3-4) ◽  
pp. 379-388
Author(s):  
Partner L. Ndlovu ◽  
Raseelo J. Moitsheki
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Heat Dissipation ◽  
Surrounding Medium ◽  
Physical Parameters ◽  
Nonlinear Boundary Value Problems ◽  
Temperature Dependent ◽  
Transform Method ◽  
Thermal Conductivity Parameter ◽  
Conductivity Parameter

AbstractIn this article, the differential transform method (DTM) is used to solve the nonlinear boundary value problems describing heat transfer in continuously moving fins undergoing convective-radiative heat dissipation. The thermal conductivity is variable and temperature dependent. The surface of the moving fin is assumed to be gray with a constant emissivity ɛ. The flow in the surrounding medium provides a constant heat transfer coefficient h over the entire surface of the moving fins. The effects of some physical parameters such as the Peclet number, Pe, thermal conductivity parameter, β, convection-conduction parameter, Nc, radiation-conduction parameter, Nr, and dimensionless convection-radiation sink temperature, θa, on the temperature distribution are illustrated and explained.

scholarly journals Natural convection and radiation in a radial porous fin with variable thermal conductivity

2014 ◽  
Vol 19 (1) ◽  
pp. 27-37 ◽  
Author(s):  
M.T. Darvishi ◽  
F. Kani ◽  
R.S.R. Gorla
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Natural Convection ◽  
Convection Heat Transfer ◽  
Variable Thermal Conductivity ◽  
Dimensionless Temperature ◽  
Porous Fin ◽  
Rectangular Profile ◽  
Conductivity Parameter ◽  
Effects Of Radiation

Abstract In this study, the effects of radiation and convection heat transfer in a radial porous fin are considered. The geometry considered is that of a rectangular profile fin. The porous fin allows the flow to infiltrate through it and solid-fluid interaction takes place. This study is performed using Darcy’s model to formulate the heat transfer equation. The thermal conductivity is assumed to be a function of temperature. The effects of the natural convection parameter Nc , radiation parameter Nr and thermal conductivity parameter m on the dimensionless temperature distribution and heat transfer rate are discussed. The results suggest that the radiation transfers more heat than a similar model without radiation

Heat transfer enhancement of hybrid nanofluids over porous cone

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Umar Farooq ◽  
Hassan Waqas ◽  
Taseer Muhammad ◽  
Shan Ali Khan
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Differential Equations ◽  
Base Fluid ◽  
Volume Fraction ◽  
Flow Parameters ◽  
Heat Efficiency ◽  
Thermal Conductivity Parameter ◽  
Nanoparticles Volume Fraction ◽  
Conductivity Parameter

Abstract The nanofluid is most advantageous to enhance the heat efficiency of base fluid by submerging solid nanoparticles in it. The metals, oxides, and carbides are helpful to improve the heat transfer rate. In the present analysis, the role of the slip phenomenon in the radiative flow of hybrid nanoliquid containing SiO2 silicon dioxide and CNTs over in the porous cone is scrutinized. The behavior of the magnetic field, thermal conductivity, and thermal radiation are examined. Here the base fluid ethylene glycol water (C2H6O2−H2O) is used. Accepting similarity transformation converts the controlling partial differential equations (PDEs) into ordinary differential equations (ODEs). The numerical solution is obtained by utilizing the Lobatto-IIIa method. The significant physical flow parameters are discussed by utilizing tables and graphs. Final remarks are demonstrating the velocity profile is declined via higher magnetic parameter while boosted up for nanoparticles volume fraction. Furthermore, the thermal profile is enriching via thermal conductivity parameter, radiation parameter, and nanoparticles volume fraction.

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