Effects of Energy Dissipation and Variable Thermal Conductivity on Entropy Generation Rate in Mixed Convection Flow

2018 ◽  
Vol 10 (4) ◽  
Author(s):  
Muhammad Qasim ◽  
Muhammad Idrees Afridi
Keyword(s):  
Thermal Conductivity ◽  
Energy Dissipation ◽  
Mixed Convection ◽  
Entropy Generation ◽  
Variable Thermal Conductivity ◽  
Convection Flow ◽  
Mixed Convection Flow ◽  
Entropy Generation Number ◽  
Similarity Transformations ◽  
Generation Number

Analysis of entropy generation in mixed convection flow over a vertically stretching sheet has been carried out in the presence of variable thermal conductivity and energy dissipation. Governing equations are reduced to self-similar ordinary differential equations via similarity transformations and are solved numerically by applying shooting and fourth-order Runge–Kutta techniques. The expressions for entropy generation number and Bejan number are also obtained by using similarity transformations. The influence of embedding physical parameters on quantities of interest is discussed through graphical illustrations. The results reveal that entropy generation number increases significantly in the vicinity of stretching surface and gradually dies out as one move away from the sheet. Also, the entropy generation number decreases with an increase in temperature difference parameter. Moreover, entropy generation number enhances with an enhancement in the Eckert number, Prandtl number, and variable thermal conductivity parameter.

Minimization of Entropy Generation in MHD Mixed Convection Flow with Energy Dissipation and Joule Heating: Utilization of Sparrow-Quack-Boerner Local Non-Similarity Method

2018 ◽  
Vol 387 ◽  
pp. 63-77 ◽  
Author(s):  
M. Idrees Afridi ◽  
Muhammad Qasim ◽  
Najeeb Alam Khan ◽  
Oluwole Daniel Makinde
Keyword(s):  
Energy Dissipation ◽  
Mixed Convection ◽  
Entropy Generation ◽  
Joule Heating ◽  
Convection Flow ◽  
Physical Parameters ◽  
Mixed Convection Flow ◽  
Entropy Analysis ◽  
Entropy Generation Number ◽  
Similarity Method

This article aims to present the non-similar solution of MHD mixed convection flow using the Sparrow-Quack-Boerner local non-similarity method. Entropy analysis is also performed in the presence of energy dissipation and Joule heating. The buoyancy parameter is chosen as the non-similarity variable and the equations are derived up to the second level of truncation. The dependency of dimensionless velocity profile, temperature distribution, Bejan and entropy generation number on physical parameters has been discussed. As far as the knowledge of the authors is concerned, no attempt has been made on the entropy analysis of MHD mixed convection flow by the local non-similarity method.

Mixed convection flow of viscoelastic nanofluid by a cylinder with variable thermal conductivity and heat source/sink

2016 ◽  
Vol 26 (1) ◽  
pp. 214-234 ◽  
Author(s):  
T. Hayat ◽  
M. Waqas ◽  
Sabir Ali Shehzad ◽  
A. Alsaedi
Keyword(s):  
Thermal Conductivity ◽  
Heat Source ◽  
Mixed Convection ◽  
Variable Thermal Conductivity ◽  
Convection Flow ◽  
Mixed Convection Flow ◽  
Viscoelastic Parameter ◽  
Content Type ◽  
Viscoelastic Nanofluid ◽  
Source Sink

Purpose – The purpose of this paper is to examine the effects of variable thermal conductivity in mixed convection flow of viscoelastic nanofluid due to a stretching cylinder with heat source/sink. Design/methodology/approach – The authors have computed the existence of the solution for Walter’s B and second grade fluids corresponding to Pr=0.5 and Pr=1.5. Skin-friction coefficient, local Nusselt and Sherwood numbers are computed numerically for different values of emerging parameters. Findings – A comparative study with the existing solutions in a limiting sense is made and analyzed. The authors found that the dimensionless velocity filed and momentum boundary layer thickness are increased when the values of viscoelastic parameter increase. The present non-Newtonian fluid flow reduces to the viscous flow in the absence of viscoelastic parameter. The larger values of viscoelastic parameter corresponds to the higher values of local Nusselt and Sherwood numbers. Originality/value – No such analysis exists in the literature yet.

Effects of Magnetic Field on an Unsteady Mixed Convection Flow of Nanofluids Containing Spherical and Cylindrical Nanoparticles

2016 ◽  
Vol 138 (6) ◽  
Author(s):  
Kalidas Das ◽  
Pinaki Ranjan Duari ◽  
Prabir Kumar Kundu
Keyword(s):  
Magnetic Field ◽  
Mass Transfer ◽  
Mixed Convection ◽  
Time Dependent ◽  
Convection Flow ◽  
Temperature Profiles ◽  
Mixed Convection Flow ◽  
Shooting Technique ◽  
Similarity Transformations ◽  
Unsteady Mixed Convection

The present article gives a ray of light on the effects of magnetic field on an unsteady mixed convection flow of nanofluids containing nanoparticles which are spherical and cylindrical in nature. The unsteadiness in the flow is mainly caused by time dependent stretching velocity and temperature of the sheet at the surface. The governing transportation equations are first transformed into ordinary differential equations by using similarity transformations and then solved by employing Runga–Kutta–Frelberg method with shooting technique. The influence of various parameters on velocity and temperature profiles as well as wall shear stress and the rate of mass transfer are discussed through graphs and tables. The results for regular fluid (water) from the study are in excellent agreement with the results reported in the literature.

scholarly journals Entropy Generation in Magnetohydrodynamic Mixed Convection Flow over an Inclined Stretching Sheet

Entropy ◽  
2016 ◽  
Vol 19 (1) ◽  
pp. 10 ◽  
Author(s):  
Muhammad Afridi ◽  
Muhammad Qasim ◽  
Ilyas Khan ◽  
Sharidan Shafie ◽  
Ali Alshomrani
Keyword(s):  
Mixed Convection ◽  
Entropy Generation ◽  
Stretching Sheet ◽  
Convection Flow ◽  
Mixed Convection Flow
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