scholarly journals Entropy Generation Optimization in Squeezing Magnetohydrodynamics Flow of Casson Nanofluid with Viscous Dissipation and Joule Heating Effect

Entropy ◽  
2019 ◽  
Vol 21 (8) ◽  
pp. 747 ◽  
Author(s):  
Muhammad Zubair ◽  
Zahir Shah ◽  
Abdullah Dawar ◽  
Saeed Islam ◽  
Poom Kumam ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Skin Friction ◽  
Viscous Dissipation ◽  
Entropy Generation ◽  
Joule Heating ◽  
Volume Fraction ◽  
Bejan Number ◽  
Parallel Plates ◽  
Casson Nanofluid ◽  
Porosity Parameter

In this research article, the investigation of the three-dimensional Casson nanofluid flow in two rotating parallel plates has been presented. The nanofluid has been considered in steady state. The rotating plates have been considered porous. The heat equation is considered to study the magnetic field, joule heating, and viscous dissipation impacts. The nonlinear ordinary system of equations has been solved analytically and numerically. For skin friction and Nusslt number, numerical results are tabulated. It is found that velocity declines for higher values of magnetic and porosity parameter while it is heightened through squeezing parameter. Temperature is an enhancing function for Eckert number and nanoparticles volume fraction. Entropy generation is augmented with radiation parameter, Prandtl, and Eckert numbers. The Casson, porosity, magnetic field, and rotation parameters were reduced while the squeezing and suction parameters increased the velocity profile along x-direction. The porosity parameter increased the Bejan number while the Eckert and Prandtl numbers decreased the Bejan number. Skin friction was enhanced with increasing the Casson, porosity, and magnetic parameters while it decreased with enhancing rotation and squeezing parameters. All these impacts have been shown via graphs. The influences by fluid flow parameters over skin friction and Nusselt number are accessible through tables.

scholarly journals Entropy Generation in Couette Flow Through a Deformable Porous Channel

2019 ◽  
Vol 4 (2) ◽  
pp. 575-590 ◽  
Author(s):  
G. Gopi Krishna ◽  
S. Sreenadh ◽  
A.N.S. Srinivas
Keyword(s):  
Porous Medium ◽  
Temperature Distribution ◽  
Couette Flow ◽  
Entropy Generation ◽  
Volume Fraction ◽  
Fluid Velocity ◽  
Porous Channel ◽  
Injection Velocity ◽  
Bejan Number ◽  
Parallel Plates

AbstractThe present study examines the entropy generation on Couette flow of a viscous fluid in parallel plates filled with deformable porous medium. The fluid is injected into the porous channel perpendicular to the lower wall with a constant velocity and is sucked out of the upper wall with same velocity .The coupled phenomenon of the fluid flow and solid deformation in the porous medium is taken in to consideration. The exact expressions for the velocity of fluid, solid displacement and temperature distribution are found analytically. The effect of pertinent parameters on the fluid velocity, solid displacement and temperature profiles are discussed in detail. In the deformable porous layer, it is noticed that the velocity of fluid, solid displacement and temperature distribution are decreases with increasing the suction/injection velocity parameter. The results obtained for the present flow characteristic reveal several interesting behaviors that warrant further study on the deformable porous media. Furthermore, the significance of drag and the volume fraction on entropy generation number and Bejan number are discussed with the help of graphs.

scholarly journals Rotating flow of viscous nanomaterial with radiation and entropy generation

2021 ◽  
Vol 13 (8) ◽  
pp. 168781402110421
Author(s):  
Tasawar Hayat ◽  
Muhammad Waqar Ahmad ◽  
Sohail A Khan ◽  
Ahmed Alsaedi
Keyword(s):  
Carbon Nanotubes ◽  
Reynolds Number ◽  
Nusselt Number ◽  
Skin Friction ◽  
Entropy Generation ◽  
Thermal Field ◽  
Bejan Number ◽  
Parallel Plates ◽  
Communication Models ◽  
Prandtl Numbers

This communication models the flow of viscous nanofluid between two heated parallel plates with radiation and uniform suction at one boundary. Two types of carbon nanotubes (CNTs) namely the single (SWCNT) and multiple (MWCNT) walls are accounted. Heat generation, radiation, and dissipation in heat expression are utilized. Entropy generation and Bejan number are examined. Formulation and analysis in rotating frame are considered. Convergent solutions for velocity and temperature are constructed and interpreted. Coefficient of skin-friction and Nusselt number are tabulated and analyzed for comparative study of SWCNT and MWCNT. Correlation for skin-friction and Nusselt number are also evaluated. An enhancement in velocity profile is seen through suction variable. A reduction occurs in axial velocity for higher Reynolds number. An opposite trend is hold for thermal field through Eckert and Prandtl numbers. An intensification in temperature is noted for radiation. An amplification in entropy rate is observed through Brinkman number. Higher Reynolds number corresponds to improve Bejan number. An improvement in radiation variable lead to rises heat transfer rate for both carbon nanotubes.

Optimization of entropy generation in motion of magnetite-Fe3O4 nanoparticles due to curved stretching sheet of variable thickness

2019 ◽  
Vol 29 (9) ◽  
pp. 3347-3365
Author(s):  
Sumaira Qayyum ◽  
Tasawar Hayat ◽  
Ahmed Alsaedi
Keyword(s):  
Porous Medium ◽  
Mixed Convection ◽  
Viscous Dissipation ◽  
Entropy Generation ◽  
Variable Thickness ◽  
Stretching Sheet ◽  
Volume Fraction ◽  
Bejan Number ◽  
Content Type ◽  
Curvature Parameter

Purpose Investigation for convective flow of water-based nanofluid (composed of ferric oxide asnanoparticles) by curved stretching sheet of variable thickness is made. Bejan number andentropy generation analysis is presented in presence of viscous dissipation, mixed convectionand porous medium. Design/methodology/approach In this paper, by using NDSolve of MATHEMATICA, the nonlinear system of equations is solved. Velocity, temperature, Bejan number and entropy generation for involved dimensionless variables are discussed. Findings Increase in velocity is depicted for larger curvature parameter, and opposite trend is witnessed for higher nanoparticle volume concentration. Enhancement in temperature is seen for higher Eckert number while reverse behavior is noticed for larger curvature parameter. Entropy rate increases for variation of curvature parameter, Brinkman number and nanoparticle volume fraction. Bejan number decays for mixed convection and curvature parameters. Originality/value To the authors’ knowledge, there exists no study yet which describes flow by curved sheet of variable thickness. Such consideration with nanoparticles seems important task. Thus, the main objective here is to determine entropy generation in ferromagnetic nanofluid flow due to variable thickened curved stretching surface. Additionally, effects of Joule heating, porous medium, mixed convection and viscous dissipation are taken into account.

Interactions of Porosity-Magnetic Field and Viscous Dissipation in an Inclined Channel Type Flow

2010 ◽  
Author(s):  
Murat Havzali ◽  
Guven Komurgoz ◽  
Aytac Arikoglu ◽  
Haci Ibrahim Keser ◽  
Ibrahim Ozkol
Keyword(s):  
Magnetic Field ◽  
Viscous Dissipation ◽  
Entropy Generation ◽  
Thermal Characteristics ◽  
Darcy Number ◽  
Transverse Magnetic ◽  
Constant Heat Flux ◽  
Bejan Number ◽  
Entropy Generation Number ◽  
Inclined Channel

In this work, entropy generation due to laminar viscous incompressible flow of a conducting fluid in the presence of a transverse magnetic field in a porous inclined channel is investigated. Fully developed flow field is solved analytically whereas the solution of the energy equation is obtained by Finite Difference Method (FDM). The boundary conditions at the walls are considered to be constant heat flux. The influence of the applied magnetic field, porous medium and the viscous dissipation on velocity, temperature and entropy generation is examined. The dependence of flow and thermal characteristics on Peclet number (Pe), Brinkman number (Br), Darcy number (Da) and Hartman number (Ha) is analyzed through velocity and temperature distribution as well as Entropy generation number (Ns) and Bejan Number (Be) profiles.

scholarly journals Entropy generation analysis of nanofluid natural convection in coaxial cylinders subjected to magnetic field

2019 ◽  
Vol 23 (6 Part A) ◽  
pp. 3467-3479
Author(s):  
Essma Belahmadi ◽  
Rachid Bessaih
Keyword(s):  
Magnetic Field ◽  
Natural Convection ◽  
Entropy Generation ◽  
Volume Fraction ◽  
Solid Volume Fraction ◽  
Bejan Number ◽  
Local Entropy ◽  
Cold Temperatures ◽  
Coaxial Cylinders ◽  
Local Entropy Generation

This paper concerns with the effect of a magnetic field on the entropy generation due to natural convection of Al2O3-water nanofluid flow between coaxial cylinders of aspect ratio H/D = 2. The inner and outer cylinders are maintained at hot and cold temperatures, respectively. The top and bottom walls are thermally insulated. The finite volume method was used to discretize the mathematical equations. The present results are compared with those found in the literature, which reveal a very good agreement. The influence of dimensionless parameters such as Hartmann number, Rayleigh number, solid volume fraction of nanoparticules, ?, and inclination angle of magnetic field on streamlines, isotherms contours, local entropy generation, mean Nusselt number, total entropy generation, St, and Bejan number is discussed. The results show that the local entropy generation are strongly influenced by the application of magnetic field. The increase in heat transfer and entropy generation by adding the nanoparticles to the base fluid depends on the magnetic field strength and direction.

scholarly journals Entropy generation analysis for MHD flow of water past an accelerated plate

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Tarek N. Abdelhameed
Keyword(s):  
Magnetic Field ◽  
Entropy Generation ◽  
Transfer Problem ◽  
Finite Difference Methods ◽  
Mhd Flow ◽  
Bejan Number ◽  
Physical Conditions ◽  
Flow Parameters ◽  
The Laplace Transform ◽  
Constant Heating

AbstractThis article examines the entropy generation in the magnetohydrodynamics (MHD) flow of Newtonian fluid (water) under the effect of applied magnetic in the absence of an induced magnetic field. More precisely, the flow of water is considered past an accelerated plate such that the fluid is receiving constant heating from the initial plate. The fluid disturbance away from the plate is negligible, therefore, the domain of flow is considered as semi-infinite. The flow and heat transfer problem is considered in terms of differential equations with physical conditions and then the corresponding equations for entropy generation and Bejan number are developed. The problem is solved for exact solutions using the Laplace transform and finite difference methods. Results are displayed in graphs and tables and discussed for embedded flow parameters. Results showed that the magnetic field has a strong influence on water flow, entropy generation, and Bejan number.

scholarly journals A generalized perspective of Fourier and Fick’s laws: Magnetized effects of Cattaneo-Christov models on transient nanofluid flow between two parallel plates with Brownian motion and thermophoresis

2020 ◽  
Vol 9 (1) ◽  
pp. 201-222 ◽  
Author(s):  
Usha Shankar ◽  
Neminath B. Naduvinamani ◽  
Hussain Basha
Keyword(s):  
Brownian Motion ◽  
Joule Heating ◽  
Concentration Field ◽  
Double Diffusion ◽  
Diffusion Models ◽  
Time Dependent ◽  
Parallel Plates ◽  
Nanofluid Flow ◽  
Casson Nanofluid ◽  
Highly Nonlinear

AbstractPresent research article reports the magnetized impacts of Cattaneo-Christov double diffusion models on heat and mass transfer behaviour of viscous incompressible, time-dependent, two-dimensional Casson nanofluid flow through the channel with Joule heating and viscous dissipation effects numerically. The classical transport models such as Fourier and Fick’s laws of heat and mass diffusions are generalized in terms of Cattaneo-Christov double diffusion models by accounting the thermal and concentration relaxation times. The present physical problem is examined in the presence of Lorentz forces to investigate the effects of magnetic field on double diffusion process along with Joule heating. The non-Newtonian Casson nanofluid flow between two parallel plates gives the system of time-dependent, highly nonlinear, coupled partial differential equations and is solved by utilizing RK-SM and bvp4c schemes. Present results show that, the temperature and concentration distributions are fewer in case of Cattaneo-Christov heat and mass flux models when compared to the Fourier’s and Fick’s laws of heat and mass diffusions. The concentration field is a diminishing function of thermophoresis parameter and it is an increasing function of Brownian motion parameter. Finally, an excellent comparison between the present solutions and previously published results show the accuracy of the results and methods used to achieve the objective of the present work.

Analysis of the Effects of Joule Heating and Viscous Dissipation on Combined Pressure-Driven and Electrokinetic Flows in a Two-Parallel Plate Channel with Unequal Constant Temperatures

2018 ◽  
Vol 233 (4) ◽  
pp. 871-879 ◽  
Author(s):  
Harshad Sanjay Gaikwad ◽  
Pranab Kumar Mondal ◽  
Dipankar Narayan Basu ◽  
Nares Chimres ◽  
Somchai Wongwises
Keyword(s):  
Viscous Dissipation ◽  
Entropy Generation ◽  
Joule Heating ◽  
Generation Rate ◽  
Entropy Generation Rate ◽  
Local Entropy ◽  
Temperature Dependent ◽  
Temperature Dependent Viscosity ◽  
Dependent Viscosity ◽  
Local Entropy Generation

In this article, we perform an entropy generation analysis for the micro channel heat sink applications where the flow of fluid is actuated by combined influences of applied pressure gradient and electric field under electrical double layer phenomenon. The upper and lower walls of the channels are kept at different constant temperatures. The temperature-dependent viscosity of the fluid is considered and hence the momentum equation and energy equations are coupled in this study. Also, a hydrodynamic slip condition is employed on the viscous dissipation. For complete analysis of the entropy generation, we use a perturbation approach with lubrication approximation. In this study, we discuss the results depicting variations in the velocity and temperature distributions and their effect on local entropy generation rate and Bejan number in the system. It can be summarized from this analysis that the enhanced velocity gradients in the flow field due to combined effect of temperature-dependent viscosity and Joule heating and viscous dissipative effects, leads to an enhancement in the local entropy generation rate in the system.

Second Law Analysis of Magnetorheological Rotational Flow With Viscous Dissipation

2016 ◽  
Vol 8 (2) ◽  
Author(s):  
Abbas Hazbavi
Keyword(s):  
Magnetic Field ◽  
Viscous Dissipation ◽  
Entropy Generation ◽  
Hartmann Number ◽  
Outer Cylinder ◽  
Base Flow ◽  
Convection Flow ◽  
Fluid Temperature ◽  
Brinkman Number ◽  
Fluid Elasticity

In this study, the influences of the applied magnetic field and fluid elasticity were investigated for a nonlinear viscoelastic fluid obeying the Carreau equation between concentric annulus where the inner cylinder rotates at a constant angular velocity and the outer cylinder is stationary. The governing motion and energy balance equations are coupled while viscous dissipation is taken into account, adding complexity to the already highly correlated set of differential equations. The numerical solution is obtained for the narrow gap limit and steady-state base flow. Magnetic field effect on local entropy generation due to steady two-dimensional laminar forced convection flow was investigated. This study was focused on the entropy generation characteristics and its dependency on various dimensionless parameters. The effects of the Hartmann number, the Brinkman number, the Deborah number, and the fluid elasticity on the stability of the flow were investigated. The application of the magnetic field induces a resistive force acting in the opposite direction of the flow, thus causing its deceleration. Moreover, the study shows that the presence of magnetic field tends to slowdown the fluid motion and thus increases the fluid temperature. However, the total entropy generation number decreases as the Hartmann number and fluid elasticity increase and it increases with increasing Brinkman number.

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