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.

scholarly journals Numerical Simulation on Convection and Thermal Radiation of Casson Fluid in an Enclosure with Entropy Generation

Entropy ◽  
2020 ◽  
Vol 22 (2) ◽  
pp. 229 ◽  
Author(s):  
A. K. Alzahrani ◽  
S. Sivasankaran ◽  
M. Bhuvaneswari
Keyword(s):  
Numerical Simulation ◽  
Aspect Ratio ◽  
Thermal Radiation ◽  
Entropy Generation ◽  
Energy Transport ◽  
Casson Fluid ◽  
Radiation Parameter ◽  
Fluid Parameter ◽  
The Impact ◽  
Thermal Energy Transport

The goal of the current numerical simulation is to explore the impact of aspect ratio, thermal radiation, and entropy generation on buoyant induced convection in a rectangular box filled with Casson fluid. The vertical boundaries of the box are maintained with different constant thermal distribution. Thermal insulation is executed on horizontal boundaries. The solution is obtained by a finite volume-based iterative method. The results are explored over a range of radiation parameter, Casson fluid parameter, aspect ratio, and Grashof number. The impact of entropy generation is also examined in detail. Thermal stratification occurs for greater values of Casson liquid parameters in the presence of radiation. The kinetic energy grows on rising the values of Casson liquid and radiation parameters. The thermal energy transport declines on growing the values of radiation parameter and it enhances on rising the Casson fluid parameter.

Numerical Study on Mixed Convection and Entropy Generation of a Nanofluid in a Lid-Driven Square Enclosure

2015 ◽  
Vol 138 (1) ◽  
Author(s):  
R. K. Nayak ◽  
S. Bhattacharyya ◽  
I. Pop
Keyword(s):  
Heat Transfer ◽  
Mixed Convection ◽  
Entropy Generation ◽  
Volume Fraction ◽  
Numerical Study ◽  
Control Volume ◽  
Transport Equations ◽  
Bejan Number ◽  
Square Enclosure ◽  
Wide Range

A numerical investigation of mixed convection due to a copper–water nanofluid in an enclosure is presented. The mixed convection is governed by moving the upper lid of the enclosure and imposing a vertical temperature gradient. The transport equations for fluid and heat are modeled by using the Boussinesq approximation. A modified form of the control volume based SIMPLET algorithm is used for the solution of the transport equations. The fluid flow and heat transfer characteristics are studied for a wide range of Reynolds number and Grashof number so as to have the Richardson number greater or less than 1. The nanoparticle volume fraction is considered up to 20%. Heat flow patterns are analyzed through the energy flux vector. The rate of enhancement in heat transfer due to the addition of nanoparticles is analyzed. The entropy generation and Bejan number are evaluated to demonstrate the thermodynamic optimization of the mixed convection. We have obtained the enhancement rate in heat transfer and entropy generation in nanofluid for a wide range of parameter values.

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.

Entropy generation analysis of nanoliquid flow through microchannel considering heat source and different shapes of nanoparticle

2019 ◽  
Vol 30 (3) ◽  
pp. 1457-1477 ◽  
Author(s):  
B.J. Gireesha ◽  
S. Sindhu
Keyword(s):  
Thermal Conductivity ◽  
Heat Source ◽  
Entropy Generation ◽  
Volume Fraction ◽  
Internal Heat ◽  
Bejan Number ◽  
Molybdenum Disulphide ◽  
Content Type ◽  
Different Shapes ◽  
The Impact

Purpose This paper aims to focus on the steady state flow of nanoliquid through microchannel with the aid of internal heat source and different shapes of nanoparticle. The influence of MoS2 and TiO2 particles of nano size on flow and thermal fields is examined. The governing equations are modelled and then solved numerically. The obtained physical model is nondimensionalized using dimensionless quantities. The nondimensional equations are treated with numerical scheme. The outcome of the current work is presented graphically. Diverse substantial quantities such as entropy generation, Bejan number and Nusselt number for distinct parameters are depicted through graphs. The result established that nanoparticle of blade shape acquires larger thermal conductivity. Entropy analysis is carried out to explore the impact of various parameters such as nanoparticle volume fraction, magnetic parameter, radiation parameter and heat source parameter. Design/methodology/approach The resultant boundary value problem is converted into initial value problem using shooting scheme. Then the flow model is resolved using Runge-Kutta-Fehlberg-Fourth-Fifth order technique. Findings It is emphasized that entropy generation for the fluid satisfies N(ζ)(TiO2−water) > N(ζ)(MoS2−water). In addition to this, it is emphasized that N(ζ)sphere > N(ζ)brick > N(ζ)cylinder > N(ζ)platelet > N(ζ)blade. Also, it is obtained that blade-shaped nanoparticle has higher thermal conductivity for both MoS2 and TiO2. Originality/value Shape effects on Molybdenum disulphide and TiO2 nanoparticle in a microchannel with heat source is examined. The analysis of entropy shows that N(ζ)(TiO2−water) > N(ζ)(MoS2−water).

scholarly journals ENTROPY GENERATION IN MHD FLOW THROUGH A DEFORMABLE POROUS LAYER WITH CONSTANT INJECTION/ SUCTION AT THE BOUNDARY

2021 ◽  
Vol 51 (4) ◽  
pp. 249-254
Author(s):  
Utpal Jyoti Das
Keyword(s):  
Porous Layer ◽  
Entropy Generation ◽  
Volume Fraction ◽  
Fluid Velocity ◽  
Mhd Flow ◽  
Bejan Number ◽  
Solid Deformation ◽  
Dimensional Parameters ◽  
Flow Through ◽  
The Impact

The present paper examines the entropy generation on MHD flow of viscous fluid over a deformable vertical porous layer with constant injection/ suction velocity at the   boundary walls of the layer. The combined phenomenon of the solid deformation and fluid movement in the porous medium are taken into consideration. The influence of relevant non-dimensional parameters on the fluid velocity, solid displacement, temperature and concentration profiles are discussed. Also, the impact of Brinkman number, volume fraction parameter and drag parameter on entropy generation and Bejan number are discussed.

scholarly journals Entropy Analysis on a Three-Dimensional Wavy Flow of Eyring–Powell Nanofluid: A Comparative Study

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Arshad Riaz ◽  
Ahmed Zeeshan ◽  
M. M. Bhatti
Keyword(s):  
Viscous Dissipation ◽  
Newtonian Fluid ◽  
Entropy Generation ◽  
Pressure Rise ◽  
Software Tool ◽  
Bejan Number ◽  
Mathematical Treatment ◽  
Cylindrical Domain ◽  
Special Cases ◽  
The Impact

The thermal management of a system needs an accurate and efficient measurement of exergy. For optimal performance, entropy should be minimized. This study explores the enhancement of the thermal exchange and entropy in the stream of Eyring–Powell fluid comprising nanoparticles saturating the vertical oriented dual cylindrical domain with uniform thermal conductivity and viscous dissipation effects. A symmetrical sine wave over the walls is used to induce the flow. The mathematical treatment for the conservation laws are described by a set of PDEs, which are, later on, converted to ordinary differential equations by homotopy deformations and then evaluated on the Mathematica software tool. The expression of the pressure rise term has been handled numerically by using numerical integration by Mathematica through the algorithm of the Newton–Cotes formula. The impact of the various factors on velocity, heat, entropy profile, and the Bejan number are elaborated pictorially and tabularly. The entropy generation is enhanced with the variation of viscous dissipation but reduced in the case of the concentration parameter, but viscous dissipation reveals opposite findings for the Newtonian fluid. From the abovementioned detailed discussion, it can be concluded that Eyring–Powell shows the difference in behavior in the entropy generation and in the presence of nanoparticles due to the significant dissipation effects, and also, it travels faster than the viscous fluid. A comparison between the Eyring-Powell and Newtonian fluid are also made for each pertinent parameter through special cases. This study may be applicable for cancer therapy in biomedicine by nanofluid characteristics in various drugs considered as a non-Newtonian fluid.

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.

scholarly journals Mixed Convection and Entropy Generation of an Ag-Water Nanofluid in an Inclined L-Shaped Channel

Energies ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 1150 ◽  
Author(s):  
Taher Armaghani ◽  
Muneer Ismael ◽  
Ali Chamkha ◽  
Ioan Pop
Keyword(s):  
Nusselt Number ◽  
Mixed Convection ◽  
Entropy Generation ◽  
Richardson Number ◽  
Volume Fraction ◽  
Governing Equations ◽  
Nanoparticles Volume Fraction ◽  
The Mean ◽  
The Right ◽  
Volume Method

This paper investigates the mixed convection and entropy generation of an Ag-water nanofluid in an L-shaped channel fixed at an inclination angle of 30° to the horizontal axis. An isothermal heat source was positioned in the middle of the right inclined wall of the channel while the other walls were kept adiabatic. The finite volume method was used for solving the problem’s governing equations. The numerical results were obtained for a range of pertinent parameters: Reynolds number, Richardson number, aspect ratio, and the nanoparticles volume fraction. These results were Re = 50–200; Ri = 0.1, 1, 10; AR = 0.5–0.8; and φ = 0.0–0.06, respectively. The results showed that both the Reynolds and the Richardson numbers enhanced the mean Nusselt number and minimized the rate of entropy generation. It was also found that when AR. increased, the mean Nusselt number was enhanced, and the rate of entropy generation decreased. The nanoparticles volume fraction was predicted to contribute to increasing both the mean Nusselt number and the rate of entropy generation.

scholarly journals Optimal Design of Nanoparticle Enhanced Phan-Thien–Tanner Flow of a Viscoelastic Fluid in a Microchannel

Entropy ◽  
2018 ◽  
Vol 20 (12) ◽  
pp. 895
Author(s):  
Mohammad Abdollahzadeh Jamalabadi
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Entropy Generation ◽  
Volume Fraction ◽  
Circular Cross Section ◽  
Major Influence ◽  
Parameter Study ◽  
Bejan Number ◽  
Total Entropy ◽  
Minimum Entropy

The excellent thermal characteristics of nanoparticles have increased their application in the field of heat transfer. In this paper, a thermophysical and geometrical parameter study is performed to minimize the total entropy generation of the viscoelastic flow of nanofluid. Entropy generation with respect to volume fraction (<0.04), the Reynolds number (20,000–100,000), and the diameter of the microchannel (20–20,000 μm) with the circular cross-section under constant flux are calculated. As is shown, most of the entropy generation owes to heat transfer and by increasing the diameter of the channel, the Bejan number increases. The contribution of heat entropy generation in the microchannel is very poor and the major influence of entropy generation is attributable to friction. The maximum quantity of in-channel entropy generation happens in nanofluids with TiO2, CuO, Cu, and Ag nanoparticles, in turn, despite the fact in the microchannel this behavior is inverted, the minimum entropy generation occurs in nanofluids with CuO, Cu, Ag, and TiO2 nanoparticles, in turn. In the channel and microchannel for all nanofluids except water-TiO2, increasing the volume fraction of nanoparticles decreases entropy generation. In the channel and microchannel the total entropy generation increases by augmentation the Reynolds number.

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