scholarly journals Entropy Generation in MHD Eyring–Powell Fluid Flow over an Unsteady Oscillatory Porous Stretching Surface under the Impact of Thermal Radiation and Heat Source/Sink

2018 ◽  
Vol 8 (12) ◽  
pp. 2588 ◽  
Author(s):  
Sayer Alharbi ◽  
Abdullah Dawar ◽  
Zahir Shah ◽  
Waris Khan ◽  
Muhammad Idrees ◽  
...  
Keyword(s):  
Heat Source ◽  
Thermal Radiation ◽  
Entropy Generation ◽  
Stretching Sheet ◽  
Generation Rate ◽  
Entropy Generation Rate ◽  
Bejan Number ◽  
Temperature Function ◽  
Source Sink ◽  
The Impact

In this article, we have briefly examined the entropy generation in magnetohydrodynamic (MHD) Eyring–Powell fluid over an unsteady oscillating porous stretching sheet. The impact of thermal radiation and heat source/sink are taken in this investigation. The impact of embedded parameters on velocity function, temperature function, entropy generation rate, and Bejan number are deliberated through graphs, and discussed as well. By studying the entropy generation in magnetohydrodynamic Eyring–Powell fluid over an unsteady oscillating porous stretching sheet, the entropy generation rate is reduced with escalation in porosity, thermal radiation, and magnetic parameters, while increased with the escalation in Reynolds number. Also, the Bejan number is increased with the escalation in porosity and magnetic parameter, while increased with the escalation in thermal radiation parameter. The impact of skin fraction coefficient and local Nusselt number are discussed through tables. The partial differential equations are converted to ordinary differential equation with the help of similarity variables. The homotopy analysis method (HAM) is used for the solution of the problem. The results of this investigation agree, satisfactorily, with past studies.

scholarly journals Entropy Generation in MHD Radiative Flow of CNTs Casson Nanofluid in Rotating Channels with Heat Source/Sink

2019 ◽  
Vol 2019 ◽  
pp. 1-14 ◽  
Author(s):  
Poom Kumam ◽  
Zahir Shah ◽  
Abdullah Dawar ◽  
Haroon Ur Rasheed ◽  
Saeed Islam
Keyword(s):  
Heat Source ◽  
Entropy Generation ◽  
Second Law Of Thermodynamics ◽  
Entropy Generation Rate ◽  
Physical Parameters ◽  
Bejan Number ◽  
Surface Drag ◽  
Casson Nanofluid ◽  
Source Sink ◽  
The Impact

We presented the applications of entropy generation for SWCNTs and MWCNTs based on kerosene oil for Casson nanofluid flow by rotating channels. Kerosene oil has advanced thermal conductivity and exclusive features and has a lot of practical uses due to its unique behavior. That is why we have used kerosene oil as a based fluid. For the entropy generation second law of thermodynamics is applied and implemented for the nanofluid transport mechanism. In the presence of magnetic field, the effects of thermal radiations and heat source/sink on the temperature profiles are studied. The fluid flow is supposed in steady state. With the help of suitable similitude parameters, the leading equations have been transformed to a set of differential equations. The solution of the modeled problem has been carried out with the homotopic approach. The physical properties of carbon nanotubes are shown through tables. The effects of the imbedded physical parameters on the velocities, temperature, entropy generation rate, and Bejan number profiles are investigated and presented through graphs. Moreover, the impact of significant parameters on surface drag force and heat transfer rate is tabulated.

Entropy Analysis in MHD Flow with Heat Source and Thermal Radiation Past a Stretching Sheet in a Porous Medium

2018 ◽  
Vol 387 ◽  
pp. 364-372 ◽  
Author(s):  
Oluwole Daniel Makinde ◽  
Adetayo Samuel Eegunjobi
Keyword(s):  
Porous Medium ◽  
Heat Source ◽  
Thermal Radiation ◽  
Entropy Generation ◽  
Stretching Sheet ◽  
Fluid Velocity ◽  
Entropy Generation Rate ◽  
Integration Scheme ◽  
Bejan Number ◽  
Medium Permeability

In this paper, we conducted the thermodynamics first and second laws analyses on hydromagnetic boundary layer flow of an incompressible electrically conducting viscous fluid past a vertically stretching sheet embedded in a porous medium with heat source and thermal radiation. The governing equations describing the problem are converted to a system of nonlinear ordinary differential equations using appropriate similarity variables. Using shooting technique coupled with Runge-Kutta-Ferhlberg integration scheme, the model boundary value problem is numerically tackled. The parametric effects on fluid velocity, temperature, skin friction, Nusselt number, entropy generation rate and the Bejan number are presented graphically and discussed quantitatively. Our results revealed among others, that the entropy generation is enhanced by magnetic field, thermal radiation and heat source but lessened by increasing porous medium permeability and buoyancy force.

Entropy generation in radiative flow of Ree-Eyring fluid due to due rotating disks

2019 ◽  
Vol 29 (6) ◽  
pp. 2057-2079 ◽  
Author(s):  
Muhammad Ijaz Khan ◽  
Sohail Ahmad Khan ◽  
Tasawar Hayat ◽  
Muhammad Faisal Javed ◽  
Ahmed Alsaedi
Keyword(s):  
Heat Transfer ◽  
Entropy Generation ◽  
Magnetic Parameter ◽  
Nonlinear Flow ◽  
Generation Rate ◽  
Entropy Generation Rate ◽  
Bejan Number ◽  
Rotating Disks ◽  
Content Type ◽  
The Impact

Purpose This study aims to examine the flow characteristics of Ree–Eyring fluid between two rotating disks. The characteristics of heat transfer are discussed in presence of viscous dissipation, heat source/sink and nonlinear radiative heat flux. Design/methodology/approach Nonlinear flow expressions lead to ordinary ones through adequate similarity transformations. The ordinary differential system has been tackled through optimal homotopic method. The impact of different flow variables on the velocity field, entropy generation rate and temperature fields is graphically discussed. The surface drag force and heat transfer rate are numerically examined via various pertinent parameters. Findings By minimization of values of stretching parameter and Brinkman number, the entropy generation rate can be controlled. The entropy generation rate enhances for higher values of magnetic parameter, while the Bejan number is decreased via magnetic parameter. Originality/value No such work is yet published in the literature.

Thermodynamics Analysis of Unsteady MHD Mixed Convection with Slip and Thermal Radiation over a Permeable Surface

2017 ◽  
Vol 374 ◽  
pp. 29-46 ◽  
Author(s):  
Ahmad Muhammad ◽  
Oluwole Daniel Makinde
Keyword(s):  
Magnetic Field ◽  
Differential Equations ◽  
Thermal Radiation ◽  
Entropy Generation ◽  
Temperature Jump ◽  
Velocity Slip ◽  
Generation Rate ◽  
Entropy Generation Rate ◽  
Bejan Number ◽  
Local Similarity

This paper discusses the thermodynamics irreversibility in an unsteady hydromagnetic mixed convective flow of an electrically conducting optically dense fluid over a permeable vertical surface under the combined influence of thermal radiation, velocity slip, temperature jump, buoyancy force, viscous dissipation, Joule heating and magnetic field. The governing partial differential equations are reduced to ordinary differential equations by using similarity variable. A local similarity solution is obtained numerically using shooting technique coupled with Runge-Kutta Fehlberg integration method. The influence of various thermophysical parameters on velocity and temperature profiles, skin friction, Nusselt number, entropy generation rate and Bejan number are presented graphically and discussed quantitatively. It is found that velocity slip, surface injection and temperature jump can successfully reduce entropy generation rate in the presence of an applied magnetic field. A comparison of numerical solution is made with the exact solution under a special case scenario and excellent agreement is found.

MHD and nonlinear thermal radiation effects on hybrid nanofluid past a wedge with heat source and entropy generation

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Fazle Mabood ◽  
Anum Shafiq ◽  
Waqar Ahmed Khan ◽  
Irfan Anjum Badruddin
Keyword(s):  
Heat Transfer ◽  
Differential Equations ◽  
Heat Source ◽  
Thermal Radiation ◽  
Entropy Generation ◽  
Entropy Generation Rate ◽  
Design Parameters ◽  
Hybrid Nanofluid ◽  
Nonlinear Thermal Radiation ◽  
Content Type

Purpose This study aims to investigate the irreversibility associated with the Fe3O4–Co/kerosene hybrid-nanofluid past a wedge with nonlinear radiation and heat source. Design/methodology/approach This study reports the numerical analysis of the hybrid nanofluid model under the implications of the heat source and magnetic field over a static and moving wedge with slips. The second law of thermodynamics is applied with nonlinear thermal radiation. The system that comprises differential equations of partial derivatives is remodeled into the system of differential equations via similarity transformations and then solved through the Runge–Kutta–Fehlberg with shooting technique. The physical parameters, which emerges from the derived system, are discussed in graphical formats. Excellent proficiency in the numerical process is analyzed by comparing the results with available literature in limiting scenarios. Findings The significant outcomes of the current investigation are that the velocity field uplifts for higher velocity slip and magnetic strength. Further, the heat transfer rate is reduced with the incremental values of the Eckert number, while it uplifts with thermal slip and radiation parameters. An increase in Brinkmann’s number uplifts the entropy generation rate, while that peters out the Bejan number. The results of this study are of importance involving in the assessment of the effect of some important design parameters on heat transfer and, consequently, on the optimization of industrial processes. Originality/value This study is original work that reports the hybrid nanofluid model of Fe3O4–Co/kerosene.

Aerodynamic Optimization Design of Airfoil Shape Using Entropy Generation as an Objective

2018 ◽  
Vol 11 (2) ◽  
Author(s):  
Wei Wang ◽  
Jun Wang ◽  
Xiao-Pei Yang ◽  
Yan-Yan Ding
Keyword(s):  
Entropy Generation ◽  
Energy Cost ◽  
Optimization Design ◽  
Generation Rate ◽  
Entropy Generation Rate ◽  
Aerodynamic Optimization ◽  
Analysis And Design ◽  
Constraint Model ◽  
The Impact ◽  
Drag Ratio

Abstract An entropy analysis and design optimization methodology is combined with airfoil shape optimization to demonstrate the impact of entropy generation on aerodynamics designs. In the work herein, the entropy generation rate is presented as an extra design objective along with lift-drag ratio, while the lift coefficient is the constraint. Model equation, which calculates the local entropy generation rate in turbulent flows, is derived by extending the Reynolds-averaging of entropy balance equation. The class-shape function transform (CST) parametric method is used to model the airfoil configuration and combine the radial basis functions (RBFs) based mesh deformation technique with flow solver to compute the quantities such as lift-drag ratio and entropy generation at the design condition. From the multi-objective solutions which represent the best trade-offs between the design objectives, one can select a set of airfoil shapes with a low relative energy cost and with improved aerodynamic performance. It can be concluded that the methodology of entropy generation analysis is an effective tool in the aerodynamic optimization design of airfoil shape with the capability of determining the amount of energy cost.

scholarly journals Effects of Entropy Generation, Thermal Radiation and Moving-Wall Direction on Mixed Convective Flow of Nanofluid in an Enclosure

Mathematics ◽  
2020 ◽  
Vol 8 (9) ◽  
pp. 1471
Author(s):  
Sivasankaran Sivanandam ◽  
Ali J. Chamkha ◽  
Fouad O. M. Mallawi ◽  
Metib S. Alghamdi ◽  
Aisha M. Alqahtani
Keyword(s):  
Thermal Radiation ◽  
Entropy Generation ◽  
Energy Transport ◽  
Volume Fraction ◽  
Control Volume ◽  
Bejan Number ◽  
Moving Wall ◽  
Mixed Convective Flow ◽  
The Right ◽  
The Impact

A numeric investigation is executed to understand the impact of moving-wall direction, thermal radiation, entropy generation and nanofluid volume fraction on combined convection and energy transfer of nanoliquids in a differential heated box. The top wall of the enclosed box is assumed to move either to the left or the right direction which affects the stream inside the box. The horizontal barriers are engaged to be adiabatic. The derived mathematical model is solved by the control volume technique. The results are presented graphically to know the impact of the dissimilar ways of moving wall, Richardson number, Bejan number, thermal radiation, cup mixing and average temperatures. It is concluded that the stream and the thermal distribution are intensely affected by the moving-wall direction. It is established that the thermal radiation enhances the convection energy transport inside the enclosure.

Entropy generation and heat transport analysis of Casson fluid flow with viscous and Joule heating in an inclined porous microchannel

2019 ◽  
Vol 233 (5) ◽  
pp. 1173-1184 ◽  
Author(s):  
BJ Gireesha ◽  
CT Srinivasa ◽  
NS Shashikumar ◽  
Madhu Macha ◽  
JK Singh ◽  
...  
Keyword(s):  
Fluid Flow ◽  
Entropy Generation ◽  
Convective Boundary Condition ◽  
Casson Fluid ◽  
Entropy Generation Rate ◽  
Bejan Number ◽  
Convective Boundary ◽  
Electrically Conducting ◽  
Number Formula ◽  
The Impact

The combined effects of the magnetic field, suction/injection, and convective boundary condition on heat transfer and entropy generation in an electrically conducting Casson fluid flow through an inclined porous microchannel are scrutinized. The temperature-dependent heat source is also accounted. Numerical simulation for the modelled problem is presented via Runge–Kutta–Felhberg-based shooting technique. Special attention is given to analyze the impact of involved parameters on the profiles of velocity [Formula: see text], temperature [Formula: see text], entropy generation [Formula: see text], and Bejan number [Formula: see text]. It is established that entropy generation rate decreases at the walls with an increase in Hartmann number [Formula: see text], while it increases at the center region of the microchannel.

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