scholarly journals Entropy Generation Analysis in a Variable Viscosity MHD Channel Flow with Permeable Walls and Convective Heating

2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
A. S. Eegunjobi ◽  
O. D. Makinde
Keyword(s):  
Entropy Generation ◽  
Variable Viscosity ◽  
Convective Heating ◽  
Bejan Number ◽  
Surface Boundary ◽  
Entropy Generation Number ◽  
Electrically Conducting ◽  
Surface Boundary Conditions ◽  
Permeable Walls ◽  
Mhd Channel

This paper examines the effects of the thermodynamic second law on steady flow of an incompressible variable viscosity electrically conducting fluid in a channel with permeable walls and convective surface boundary conditions. The nonlinear model governing equations are solved numerically using shooting quadrature. Numerical results of the velocity and temperature profiles are utilised to compute the entropy generation number and the Bejan number. The results revealed that entropy generation minimization can be achieved by appropriate combination of the regulated values of thermophysical parameters controlling the flow systems.

scholarly journals Inherent irreversibility impacts on thermal boundary layer flow over a mobile plate with convective surface boundary conditions

2019 ◽  
Vol 5 (2) ◽  
pp. 45
Author(s):  
Sajjad Haider ◽  
Adnan Saeed Butt ◽  
Asif Ali ◽  
Yun-Zhang Li ◽  
Tufail Hussain
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Temperature Profile ◽  
Entropy Generation ◽  
Free Stream ◽  
Entropy Generation Rate ◽  
Surface Boundary ◽  
Entropy Generation Number ◽  
Surface Boundary Conditions ◽  
Layer Flow

<p class="abstract"><strong>Background:</strong> The irreversibility impacts on flow and heat transfer processes can be quantified through entropy analysis. It is a significant tool which can be utilized to deduce about the energy losses. The current study investigates the inherent irreversibility impacts during a flow of boundary layer and heat transfer on a mobile plate.</p><p class="abstract"><strong>Methods:</strong> The flow is examined under thermal radiation and convective heat conditions. The fundamental governing equations of flow and heat phenomenon are transmuted into ordinary differential equations by employing similarity transmutations and shooting technique is utilized in order to solve the resultant equations. The temperature and velocity profiles are acquired to reckon Bejan and entropy generation number. Pertinent results are elucidated graphically for the movement of plate and flow in same and opposite directions.  </p><p class="abstract"><strong>Results:</strong> A decline in temperature profile is noted with rise in values of <em>Pr</em> in both cases when the movement of surface and free stream is in similar and converse directions. A decrease in temperature is observed for both cases with increase in <em>N<sub>R</sub></em> while with the rise in Biot number <em>a</em>, the temperature profile also increases. Entropy generation rate near the surface is high in case when surface and free stream are moving in opposite directions as compared to case when they move in same directions.</p><p class="abstract"><strong>Conclusions:</strong> It is observed that irreversibility impacts are more remarkable when the movement of fluid and plate is in opposite direction. Moreover, irreversibility impacts of heat transfer are prominent in free stream region.</p><p class="abstract"> </p><br /><em></em>

Effect of Slip and Convective Boundary Conditions on Entropy Generation in a Porous Channel due to Micropolar Fluid Flow

2018 ◽  
Vol 19 (1) ◽  
pp. 11-24 ◽  
Author(s):  
D. Srinivasacharya ◽  
K. Himabindu
Keyword(s):  
Entropy Generation ◽  
Micropolar Fluid ◽  
Flow Direction ◽  
Velocity Slip ◽  
Porous Channel ◽  
Convective Heating ◽  
Bejan Number ◽  
Convective Boundary ◽  
Entropy Generation Number ◽  
Axial Pressure Gradient

AbstractThis article presents the effect of convective heating and velocity slip on flow generation of an incompressible micropolar fluid through a porous channel. The flow is induced by a constant axial pressure gradient applied in the flow direction. The non-linear governing equations are linearized using the quasilinearization technique and then solved by Chebyshev spectral collocation method. The numerical values of the velocity, microrotation and temperature are used to derive the corresponding entropy generation number and Bejan number within the porous channel. The influences of pertinent parameters on velocity, microrotation, temperature, entropy generation and Bejan number are discussed through graphs. It is observed that the convective heating tends to increase the entropy generation within the channel.

Entropy Analysis of MHD Variable Thermal Conductivity Fluid Flow Past a Convectively Heated Stretching Cylinder

2018 ◽  
Vol 387 ◽  
pp. 244-259 ◽  
Author(s):  
Sanatan Das ◽  
Subhajit Chakraborty ◽  
Oluwole Daniel Makinde ◽  
Rabindra Nath Jana
Keyword(s):  
Magnetic Field ◽  
Boundary Layer ◽  
Entropy Generation ◽  
Numerical Solutions ◽  
Fluid Velocity ◽  
Convective Heating ◽  
Bejan Number ◽  
Stretching Cylinder ◽  
Entropy Analysis ◽  
Entropy Generation Number

The present study is related to entropy analysis during magnetohydrodynamic (MHD) boundary layer flow of a viscous incompressible electrically conducting fluid past a stretching cylinder with convective heating in the presence of a transverse magnetic field. The governing boundary layer equations in cylindrical form are simplified by means of appropriate similarity transformations. Numerical solutions with high precision are obtained using Runge-Kutta fourth order scheme with eminent shooting technique. The effects of the pertinent parameters on the fluid velocity, temperature, entropy generation number, Bejan number as well as the shear stress at the surface of the cylinder are discussed graphically and quantitatively. It is examined that due to the presence of magnetic field, entropy generation can be controlled and reduced. Bejan number is plotted to present a comparative analysis of entropy generation due to heat transfer and fluid friction. It is found that Bejan number is an increasing function of Biot number.

scholarly journals Entropy analysis in moving wavy surface boundary-layer

2019 ◽  
Vol 23 (1) ◽  
pp. 233-241 ◽  
Author(s):  
Ahmer Mehmood ◽  
Muhammad Iqbal ◽  
Sajid Khan ◽  
Sufian Munawar
Keyword(s):  
Heat Transfer ◽  
Entropy Generation ◽  
Wavy Surface ◽  
Bejan Number ◽  
Surface Boundary ◽  
Surface Boundary Layer ◽  
Entropy Generation Number ◽  
Keller Box Method ◽  
Generation Number ◽  
Group Parameter

It is a well-established fact that significant gain in the heat transfer rate can be obtained by altering that flat surface texture of the working body. The most convenient alteration, in view of mathematical handling, is the wavy one. Existing studies reveal that the convective heat transfer phenomenon is affected significantly due to the presence of a solid wavy surface. How does the phenomena of entropy generation is effected due to a wavy surface is the question investigated in this manuscript. The expressions for irreversibility distribution rate, Bejan number, and volumetric entropy generation number have been evaluated by Keller-Box method. The effect of important parameters of interest, such as wavy amplitude, Prandtl number, and group parameter on irreversibility distribution rate, Bejan number and entropy generation number, have been discussed in detail. The study reveals that entropy generation number decreases and irreversibility rate increases by increasing the amplitude of the wavy surface.

scholarly journals Entropy Generation of MHD Poiseuille Flow with Hall and Joule Heating Effects

2020 ◽  
Vol 14 ◽  
Keyword(s):  
Entropy Generation ◽  
Joule Heating ◽  
Poiseuille Flow ◽  
Hall Current ◽  
Coupled System ◽  
Bejan Number ◽  
Electrically Conducting ◽  
Heating Effects ◽  
Adomian Decomposition ◽  
Ion Slip

In this article investigation has been conducted on the effects of Hall parameter, rotation parameter and Joule heating on the entropy generation of fully developed electrically conducting Poiseuille flow. The coupled system of ordinary differential equations for the flow are obtained, non-dimensionalised and solutions are constructed by Adomian decomposition technique. The effects of Hall current, Ion-slip, Joule heating and magnetic parameters on the velocity, temperature, entropy generation and Bejan number are explained and shown graphically. The results indicate that fluid entropy generation is induced by increase in Hall current, rotation and Joule heating parameters. Furthermore Bejan number is accelerated by Hall current, rotation, Magnetic and Joule heating parameters which signifies that heat transfer irreversibility dominates entropy generation.

scholarly journals Entropy Optimization of Third-Grade Nanofluid Slip Flow Embedded in a Porous Sheet With Zero Mass Flux and a Non-Fourier Heat Flux Model

2020 ◽  
Vol 8 ◽  
Author(s):  
K. Loganathan ◽  
G. Muhiuddin ◽  
A. M. Alanazi ◽  
Fehaid S. Alshammari ◽  
Bader M. Alqurashi ◽  
...  
Keyword(s):  
Heat Flux ◽  
Entropy Generation ◽  
Mass Flux ◽  
Slip Flow ◽  
Porous Plate ◽  
Bejan Number ◽  
Surface Boundary ◽  
Nanoparticle Concentration ◽  
Zero Mass ◽  
Analysis Scheme

The prime objective of this article is to explore the entropy analysis of third-order nanofluid fluid slip flow caused by a stretchable sheet implanted in a porous plate along with thermal radiation, convective surface boundary, non-Fourier heat flux applications, and nanoparticle concentration on zero mass flux conditions. The governing physical systems are modified into non-linear ordinary systems with the aid of similarity variables, and the outcomes are solved by a homotopy analysis scheme. The impression of certain governing flow parameters on the nanoparticle concentration, temperature, and velocity is illustrated through graphs, while the alteration of many valuable engineering parameters viz. the Nusselt number and Sherwood number are depicted in graphs. Entropy generation with various parameters is obtained and discussed in detail. The estimation of entropy generation using the Bejan number find robust application in power engineering and aeronautical propulsion to forecast the smartness of entire system.

Thermodynamic optimization of nanofluid flow over a non-isothermal wedge with nonlinear radiation and activation energy

2021 ◽  
Author(s):  
M R Acharya ◽  
P Mishra ◽  
Satyananda Panda
Keyword(s):  
Heat Transfer ◽  
Activation Energy ◽  
Reynolds Number ◽  
Entropy Generation ◽  
Volume Fraction ◽  
Mathematical Formulation ◽  
Bejan Number ◽  
Nanofluid Flow ◽  
Entropy Generation Number ◽  
Generation Number

Abstract This paper analyses the augmentation entropy generation number for a viscous nanofluid flow over a non-isothermal wedge including the effects of non-linear radiation and activation energy. We discuss the influence of thermodynamically important parameters during the study, namely, the Bejan number, entropy generation number, and the augmentation entropy generation number. The mathematical formulation for thermal conductivity and viscosity of nanofluid for Al2O3 − EG mixture has been considered. The results were numerically computed using implicit Keller-Box method and depicted graphically. The important result is the change in augmentation entropy generation number with Reynolds number. We observed that adding nanoparticles (volume fraction) tend to enhance augmentation entropy generation number for Al2O3 − EG nanofluid. Further, the investigation on the thermodynamic performance of non-isothermal nanofluid flow over a wedge reveals that adding nanoparticles to the base fluid is effective only when the contribution of heat transfer irreversibility is more than fluid friction irreversibility. This work also discusses the physical interpretation of heat transfer irreversibility and pressure drop irreversibility. This dependency includes Reynolds number and volume fraction parameter. Other than these, the research looked at a variety of physical characteristics associated with the flow of fluid, heat and mass transfer.

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.

MHD Flow of Cu-Al2O3/Water Hybrid Nanofluid in Porous Channel: Analysis of Entropy Generation

2017 ◽  
Vol 377 ◽  
pp. 42-61 ◽  
Author(s):  
Sanatan Das ◽  
Rabindra Nath Jana ◽  
Oluwole Daniel Makinde
Keyword(s):  
Entropy Generation ◽  
Mhd Flow ◽  
Transverse Magnetic ◽  
Porous Channel ◽  
Hybrid Nanofluid ◽  
Bejan Number ◽  
Governing Equations ◽  
Transfer Enhancement ◽  
Entropy Generation Number ◽  
Channel Analysis

In this investigation, a magnetohydrodynamic (MHD) flow of AlO /water nanofluid and Cu-AlO /water hybrid nanofluid through a porous channel is analyzed in the presence of a transverse magnetic field. An exact solution of the governing equations has been obtained in closed form. The entropy generation number and the Bejan number are also obtained. The influences of each of the governing parameters on velocity, temperature, entropy generation and Bejan number are displayed graphically and the physical aspects are discussed. In addition, a comparison of the heat transfer enhancement level due to the suspension of AlO and Cu nanoparticles in water as regular nanofluids and as hybrid Cu-AlO /water nanofluid is reported.

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