scholarly journals Regular perturbation solution of Couette flow (non-Newtonian) between two parallel porous plates: a numerical analysis with irreversibility

2020 ◽  
Vol 42 (1) ◽  
pp. 127-142
Author(s):  
M. Nazeer ◽  
M. I. Khan ◽  
S. Kadry ◽  
Yuming Chu ◽  
F. Ahmad ◽  
...  
Keyword(s):  
Pressure Gradient ◽  
Entropy Generation ◽  
Shear Thickening ◽  
Second Law Of Thermodynamics ◽  
Perturbation Solution ◽  
Bejan Number ◽  
Regular Perturbation ◽  
Thickening Behavior ◽  
Upper Lid ◽  
The Given

AbstractThe unavailability of wasted energy due to the irreversibility in the process is called the entropy generation. An irreversible process is a process in which the entropy of the system is increased. The second law of thermodynamics is used to define whether the given system is reversible or irreversible. Here, our focus is how to reduce the entropy of the system and maximize the capability of the system. There are many methods for maximizing the capacity of heat transport. The constant pressure gradient or motion of the wall can be used to increase the heat transfer rate and minimize the entropy. The objective of this study is to analyze the heat and mass transfer of an Eyring-Powell fluid in a porous channel. For this, we choose two different fluid models, namely, the plane and generalized Couette flows. The flow is generated in the channel due to a pressure gradient or with the moving of the upper lid. The present analysis shows the effects of the fluid parameters on the velocity, the temperature, the entropy generation, and the Bejan number. The nonlinear boundary value problem of the flow problem is solved with the help of the regular perturbation method. To validate the perturbation solution, a numerical solution is also obtained with the help of the built-in command NDSolve of MATHEMATICA 11.0. The velocity profile shows the shear thickening behavior via first-order Eyring-Powell parameters. It is also observed that the profile of the Bejan number has a decreasing trend against the Brinkman number. When ηi → 0 (i = 1, 2, 3), the Eyring-Powell fluid is transformed into a Newtonian fluid.

scholarly journals Thermal analysis of an Eyring-Powell fluid flow-through a constricted channel

2020 ◽  
Vol 24 (2 Part B) ◽  
pp. 1207-1216 ◽  
Author(s):  
Sufian Munawar ◽  
Najma Saleem
Keyword(s):  
Entropy Generation ◽  
Perturbation Technique ◽  
Second Law Of Thermodynamics ◽  
Entropy Generation Rate ◽  
Bejan Number ◽  
Regular Perturbation ◽  
Entropy Generation Number ◽  
Irregular Shapes ◽  
Flow Through ◽  
Constricted Channel

This paper is aimed to investigate the entropy generation in a MHD convective flow of Eyring-Powell fluid through a mildly constricted channel. The constriction is assumed to be of regular or irregular shape and is presented inside the channel wall. Mathematical model is developed using the basic laws of conservation of mass, momentum, and energy. The governing equations are normalized using appropriate set of dimensionless variables and solutions are obtained by regular perturbation technique. The solutions are further used to calculate the entropy expression associated with the Second law of thermodynamics. The heat transfer characteristics, like, temperature, isotherms, entropy generation number entropy lines and the Bejan number are analyzed for the variation in magnetic field, shape parameter, and material constants. It is observed that entropy production is maximum in the narrow part of the channel. Moreover, entropy generation rate is higher for the regular parabolic shape as compared to irregular shapes of constriction.

scholarly journals Diffusive Bejan number and second law of thermodynamics toward a new dimensionless formulation of fluid dynamics laws

2019 ◽  
Vol 23 (6 Part B) ◽  
pp. 4005-4022 ◽  
Author(s):  
Michele Trancossi ◽  
Jose Pascoa
Keyword(s):  
Fluid Dynamics ◽  
Entropy Generation ◽  
Fluid Dynamic ◽  
Second Law Of Thermodynamics ◽  
Integral Form ◽  
Second Law ◽  
Bejan Number ◽  
Definition Of ◽  
New Formulation ◽  
Dimensionless Formulation

In a recent paper, Liversage and Trancossi have defined a new formulation of drag as a function of the dimensionless Bejan and Reynolds numbers. Further analysis of this hypothesis has permitted to obtain a new dimensionless formulation of the fundamental equations of fluid dynamics in their integral form. The resulting equations have been deeply discussed for the thermodynamic definition of Bejan number evidencing that the proposed formulation allows solving fluid dynamic problems in terms of entropy generation, allowing an effective optimization of design in terms of the Second law of thermodynamics. Some samples are discussed evidencing how the new formulation can support the generation of an optimized configuration of fluidic devices and that the optimized configurations allow minimizing the entropy generation.

scholarly journals Entropy Generation and Consequences of Binary Chemical Reaction on MHD Darcy–Forchheimer Williamson Nanofluid Flow Over Non-Linearly Stretching Surface

Entropy ◽  
2019 ◽  
Vol 22 (1) ◽  
pp. 18 ◽  
Author(s):  
Ghulam Rasool ◽  
Ting Zhang ◽  
Ali J. Chamkha ◽  
Anum Shafiq ◽  
Iskander Tlili ◽  
...  
Keyword(s):  
Entropy Generation ◽  
Second Law Of Thermodynamics ◽  
Magnetic Reynolds Number ◽  
Random Motion ◽  
Weissenberg Number ◽  
Brownian Diffusion ◽  
Bejan Number ◽  
Nanofluid Flow ◽  
Highly Nonlinear ◽  
Buongiorno Model

The current article aims to present a numerical analysis of MHD Williamson nanofluid flow maintained to flow through porous medium bounded by a non-linearly stretching flat surface. The second law of thermodynamics was applied to analyze the fluid flow, heat and mass transport as well as the aspects of entropy generation using Buongiorno model. Thermophoresis and Brownian diffusion is considered which appears due to the concentration and random motion of nanoparticles in base fluid, respectively. Uniform magnetic effect is induced but the assumption of tiny magnetic Reynolds number results in zero magnetic induction. The governing equations (PDEs) are transformed into ordinary differential equations (ODEs) using appropriately adjusted transformations. The numerical method is used for solving the so-formulated highly nonlinear problem. The graphical presentation of results highlights that the heat flux receives enhancement for augmented Brownian diffusion. The Bejan number is found to be increasing with a larger Weissenberg number. The tabulated results for skin-friction, Nusselt number and Sherwood number are given. A decent agreement is noted in the results when compared with previously published literature on Williamson nanofluids.

scholarly journals Mathematical Analysis on an Asymmetrical Wavy Motion of Blood under the Influence Entropy Generation with Convective Boundary Conditions

Symmetry ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 102 ◽  
Author(s):  
Arshad Riaz ◽  
Muhammad Mubashir Bhatti ◽  
Rahmat Ellahi ◽  
Ahmed Zeeshan ◽  
Sadiq M. Sait
Keyword(s):  
Boundary Conditions ◽  
Entropy Generation ◽  
Fluid Model ◽  
Order Approximation ◽  
Bejan Number ◽  
Perturbation Scheme ◽  
Convective Boundary Conditions ◽  
Regular Perturbation ◽  
Convective Boundary ◽  
Peristaltic Pumping

In this article, we discuss the entropy generation on the asymmetric peristaltic propulsion of non-Newtonian fluid with convective boundary conditions. The Williamson fluid model is considered for the analysis of flow properties. The current fluid model has the ability to reveal Newtonian and non-Newtonian behavior. The present model is formulated via momentum, entropy, and energy equations, under the approximation of small Reynolds number and long wavelength of the peristaltic wave. A regular perturbation scheme is employed to obtain the series solutions up to third-order approximation. All the leading parameters are discussed with the help of graphs for entropy and temperature profiles. The irreversibility process is also discussed with the help of Bejan number. Streamlines are plotted to examine the trapping phenomena. Results obtained provide an excellent benchmark for further study on the entropy production with mass transfer and peristaltic pumping mechanism.

scholarly journals On the Enhancement of Heat Transfer and Reduction of Entropy Generation by Asymmetric Slip in Pressure-Driven Non-Newtonian Microflows

2018 ◽  
Vol 141 (2) ◽  
Author(s):  
Vishal Anand ◽  
Ivan C. Christov
Keyword(s):  
Heat Transfer ◽  
Entropy Generation ◽  
Shear Thickening ◽  
Slip Boundary Condition ◽  
Heat Fluxes ◽  
Bejan Number ◽  
Slip Boundary ◽  
The Difference ◽  
Analytical Expressions ◽  
Pressure Driven

We study hydrodynamics, heat transfer, and entropy generation in pressure-driven microchannel flow of a power-law fluid. Specifically, we address the effect of asymmetry in the slip boundary condition at the channel walls. Constant, uniform but unequal heat fluxes are imposed at the walls in this thermally developed flow. The effect of asymmetric slip on the velocity profile, on the wall shear stress, on the temperature distribution, on the Bejan number profiles, and on the average entropy generation and the Nusselt number are established through the numerical evaluation of exact analytical expressions derived. Specifically, due to asymmetric slip, the fluid momentum flux and thermal energy flux are enhanced along the wall with larger slip, which, in turn, shifts the location of the velocity's maximum to an off-center location closer to the said wall. Asymmetric slip is also shown to redistribute the peaks and plateaus of the Bejan number profile across the microchannel, showing a sharp transition between entropy generation due to heat transfer and due to fluid flow at an off-center-line location. In the presence of asymmetric slip, the difference in the imposed heat fluxes leads to starkly different Bejan number profiles depending on which wall is hotter, and whether the fluid is shear-thinning or shear-thickening. Overall, slip is shown to promote uniformity in both the velocity field and the temperature field, thereby reducing irreversibility in this flow.

scholarly journals Entropy Generation Analysis of Power-Law Non-Newtonian Fluid Flow Caused by Micropatterned Moving Surface

2014 ◽  
Vol 2014 ◽  
pp. 1-16 ◽  
Author(s):  
M. H. Yazdi ◽  
I. Hashim ◽  
A. Fudholi ◽  
P. Ooshaksaraei ◽  
K. Sopian
Keyword(s):  
Entropy Generation ◽  
Power Law ◽  
Shear Thickening ◽  
Bejan Number ◽  
Moving Surface ◽  
Entropy Generation Number ◽  
Parallel Microchannels ◽  
Energy Equations ◽  
Pseudoplastic Fluids ◽  
Dimensionless Entropy Generation

In the present study, the first and second law analyses of power-law non-Newtonian flow over embedded open parallel microchannels within micropatterned permeable continuous moving surface are examined at prescribed surface temperature. A similarity transformation is used to reduce the governing equations to a set of nonlinear ordinary differential equations. The dimensionless entropy generation number is formulated by an integral of the local rate of entropy generation along the width of the surface based on an equal number of microchannels and no-slip gaps interspersed between those microchannels. The velocity, the temperature, the velocity gradient, and the temperature gradient adjacent to the wall are substituted into this equation resulting from the momentum and energy equations obtained numerically by Dormand-Prince pair and shooting method. Finally, the entropy generation numbers, as well as the Bejan number, are evaluated. It is noted that the presence of the shear thinning (pseudoplastic) fluids creates entropy along the surface, with an opposite effect resulting from shear thickening (dilatant) fluids.

scholarly journals Generalization of the Convective Flow of Brinkman-Type Fluid Using Fourier’s and Fick’s Laws: Exact Solutions and Entropy Generation

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Nadeem Ahmad Sheikh ◽  
Dennis Ling Chuan Ching ◽  
Ilyas Khan ◽  
Hamzah bin Sakidin
Keyword(s):  
Entropy Generation ◽  
Mass Concentration ◽  
Special Function ◽  
Time Parameter ◽  
Convection Flow ◽  
Bejan Number ◽  
Governing Equations ◽  
Free Convection Flow ◽  
Fluid Parameter ◽  
The Given

A new scheme to formulating the Caputo time-fractional model for the flow of Brinkman-type fluid between the plates was introduced by using the generalized laws of Fourier and Fick. Within a channel, free convection flow of the electrically conducted Brinkman-type fluid was considered. A newly generated transformation was applied to the heat and mass concentration equations. The governing equations were solved by the techniques of Fourier sine and the Laplace transforms. In terms of the special function, namely, the Mittag-Leffler function, final solutions were obtained. The entropy generation and Bejan number are also calculated for the given flow. To explain the conceptual arguments of the embedded parameters, separate plots are represented in figures and are often quantitatively computed and presented in tables. It is worth noting that for increasing the values of the Brinkman-type fluid parameter, the velocity profile decreases. The regression analysis shows that the variation in the velocity for time parameter is statistically significant.

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.

scholarly journals Computational study of natural convection and entropy generation in 3-D cavity with active lateral walls

2020 ◽  
Vol 24 (3 Part B) ◽  
pp. 2089-2100
Author(s):  
Abdulwahab Alnaqi ◽  
Ahmed Hussein ◽  
Lioua Kolsi ◽  
Abdullah Al-Rashed ◽  
Dong Li ◽  
...  
Keyword(s):  
Natural Convection ◽  
Rayleigh Number ◽  
Entropy Generation ◽  
Average Nusselt Number ◽  
Computational Study ◽  
Second Law Of Thermodynamics ◽  
Bejan Number ◽  
Cubical Cavity ◽  
Rayleigh Numbers ◽  
Lateral Walls

Numerical simulation of the natural convection and entropy generation in an air-filled cubical cavity with active lateral walls is performed in this work. Both the lateral front and right sidewalls are maintained at an isothermal cold temperature. While an isothermal hot temperature is applied for both the lateral back and left sidewalls. The upper and lower walls are kept adiabatic. Entropy generation rates due to the fluid friction and the heat transfer are simulated by using the Second law of thermodynamics. Results are illustrated for Rayleigh numbers varied from (103 ? Ra ? 106). It was shown that the increase in the Rayleigh number leads to increase the average Nusselt number and to decrease the Bejan number. Also, it was found that both, Sth, and Stot, increase slightly with the increase in Rayleigh number until they reach (Ra = 105) and then begin to jump after this value. After (Ra = 105), the increase in both, Stot, and Sfr, is greater than Sth. Moreover, it was observed that iso-surfaces of Stot are similar to Sth at (103 ? Ra ? 105), while they are similar to Sfr at high Rayleigh number.

scholarly journals Slip flow of Jeffrey nanofluid with activation energy and entropy generation applications

2021 ◽  
Vol 13 (3) ◽  
pp. 168781402110065
Author(s):  
Hu Ge-JiLe ◽  
Sumaira Qayyum ◽  
Faisal Shah ◽  
M Ijaz Khan ◽  
Sami Ullah Khan
Keyword(s):  
Activation Energy ◽  
Entropy Generation ◽  
Slip Flow ◽  
Graphical Analysis ◽  
Thermal Engineering ◽  
Bejan Number ◽  
Nano Technology ◽  
Flow Equations ◽  
Jeffrey Nanofluid ◽  
Buongiorno Model

The growing development in the thermal engineering and nano-technology, much attention has been paid on the thermal properties of nanoparticles which convey many applications in industrial, technological and medical era of sciences. The noteworthy applications of nano-materials included heat transfer enhancement, thermal energy, solar systems, cooling of electronics, controlling the heat mechanisms etc. Beside this, entropy generation is an optimized scheme which reflects significances in thermodynamics systems to control the higher energy efficiency. On this end, present work presents the slip flow of Jeffrey nanofluid over a stretching sheet with applications of activation energy and viscous dissipation. The entropy generation features along with Bejan number significance is also addressed in present analysis. Buongiorno model of nanofluid is used to discuss the heat and mass transfer. The formulated flow equations are attained into non-dimensional form. An appropriate ND MATHEMATICA built-in scheme is used to find the solution. The solution confirmation is verified by performing the error analysis. For developed flow model and impacted parameters, a comprehensive graphical analysis is performed. It is observed that slip phenomenon is used to decays the velocity profile. Temperature and concentration are in direct relation with Brownian motion parameter and activation energy respectively. Entropy and Bejan number have same results for greater diffusion parameter.

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