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 Numerical Investigation of Entropy Generation in Unsteady MHD Generalized Couette Flow with Variable Electrical Conductivity

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
T. Chinyoka ◽  
O. D. Makinde
Keyword(s):  
Electrical Conductivity ◽  
Couette Flow ◽  
Entropy Generation ◽  
Fluid Velocity ◽  
Bejan Number ◽  
Governing Equations ◽  
Entropy Generation Number ◽  
Thermophysical Parameters ◽  
Second Law Analysis ◽  
Finite Difference Techniques

The thermodynamic second law analysis is utilized to investigate the inherent irreversibility in an unsteady hydromagnetic generalized Couette flow with variable electrical conductivity in the presence of induced electric field. Based on some simplified assumption, the model nonlinear governing equations are obtained and solved numerically using semidiscretization finite difference techniques. Effects of various thermophysical parameters on the fluid velocity, temperature, current density, skin friction, the Nusselt number, entropy generation number, and the Bejan number are presented graphically and discussed quantitatively.

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.

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.

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.

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.

Heat Transfer and Entropy Generation Characteristics of a Non-Newtonian Fluid Squeezed and Extruded Between Two Parallel Plates

2016 ◽  
Vol 139 (2) ◽  
Author(s):  
P Kaushik ◽  
Pranab Kumar Mondal ◽  
Sukumar Pati ◽  
Suman Chakraborty
Keyword(s):  
Heat Transfer ◽  
Newtonian Fluid ◽  
Entropy Generation ◽  
Bejan Number ◽  
Engineering Systems ◽  
Power Law Model ◽  
Parallel Plates ◽  
Unsteady Heat Transfer ◽  
Thermodynamic Performance ◽  
Fluid Rheology

This study investigates the unsteady heat transfer and entropy generation characteristics of a non-Newtonian fluid, squeezed and extruded between two parallel plates. In an effort to capture the underlying thermo-hydrodynamics, the power-law model is used here to describe the constitutive behavior of the non-Newtonian fluid. The results obtained from the present analysis reveal the intricate interplay between the fluid rheology and the squeezing dynamics, toward altering the Nusselt number and Bejan number characteristics. Findings from this study may be utilized to design optimal process parameters for enhanced thermodynamic performance of engineering systems handling complex fluids undergoing simultaneous extrusion and squeezing.

scholarly journals Three-dimensional oscillating flow between two parallel plates through a porous medium

2013 ◽  
Vol 18 (4) ◽  
pp. 1025-1037
Author(s):  
M. Guria ◽  
N. Ghara ◽  
R.N. Jana
Keyword(s):  
Reynolds Number ◽  
Porous Medium ◽  
Perturbation Technique ◽  
Three Dimensional ◽  
Injection Velocity ◽  
Parallel Plates ◽  
Suction Parameter ◽  
Constant Suction ◽  
Secondary Velocity ◽  
Primary Velocity

Abstract An unsteady Couette flow between two parallel plates when upper plates oscillates in its own plane and is subjected to a constant suction and the lower plate to a injection velocity distribution through the porous medium has been analyzed. The approximate solution has been obtained using perturbation technique. It is seen that the primary velocity increases whereas the secondary velocity decreases with an increase in permeability parameter. It is also found that the primary velocity increases with an increase in the Reynolds number as well as the suction parameter. The magnitude of the secondary velocity increases near the stationary plate but decreases near the oscillating plate with an increase in the Reynolds number. Whereas, it increases with an increase in the suction parameter.

ENTROPY GENERATION FOR A NON-NEWTONIAN SHEAR THINNING FLUID WITH VISCOUS HEATING EFFECTS

2017 ◽  
Vol 41 (4) ◽  
pp. 593-607
Author(s):  
Muharrem Imal ◽  
Coskun Ozalp ◽  
Bulent Yaniktepe ◽  
Mohammed Mehdi-Rashidi ◽  
Ertac Hurdogan
Keyword(s):  
Temperature Dependence ◽  
Entropy Generation ◽  
Pseudospectral Method ◽  
Shear Thinning ◽  
Bejan Number ◽  
Parallel Plates ◽  
Heating Effects ◽  
Exponential Temperature Dependence ◽  
Power Law Index ◽  
Shear Thinning Fluid

This paper reports the entropy generation of a two-dimensional, non-isothermal, steady, hydrodynamically and thermally fully-developed flow of an incompressible, non-Newtonian shear thinning fluid between two infinite parallel plates. The inelastic fluid is modeled by a two parameter Carreau constitutive equation with an exponential temperature dependence of viscosity. Temperature dependence of the fluid is modeled through Arrhenius law. Momentum and energy balance equations, which govern the flow, are coupled, and this nonlinear boundary value problem is solved numerically using a Pseudospectral method based on the Chebyshev polynomials. The effect of various flow controlling parameters on velocity, temperature and entropy generation is analyzed. The results indicated that Brinkman number and activation energy have opposite effects on entropy generation due to heat transfer. In contrast to the power-law index, an increase in the material time constant results in a decrease in the Bejan Number.

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 Flow of a Jeffrey Fluid Between Two Long Vertical Thin Plates with Porous Medium

2018 ◽  
Vol 7 (4.10) ◽  
pp. 1059
Author(s):  
S. Sreenadh ◽  
B. Govindarajulu ◽  
A. N.S. Srinivas ◽  
R. Nageshwar Rao
Keyword(s):  
Porous Medium ◽  
Temperature Distribution ◽  
Fluid Velocity ◽  
Numerical Results ◽  
Thin Plates ◽  
Jeffrey Fluid ◽  
Runge Kutta Method ◽  
Fluid Parameter ◽  
Permeability Parameter ◽  
Order Four

The present study investigates fully developed free - convection Jeffrey fluid flow between two vertical plates with porous medium. The vertical plates are moving with same velocity but in opposite directions. The coupled nonlinear governing equations are solved by using the linearization technique. The solutions for velocity distribution, temperature distribution, skin friction and rate of heat transfer is obtained in the presence of porous medium by Iterative procedure.  Shooting technique with Runge - Kutta method of order four is proposed to compare the numerical results for velocity and temperature distribution. The numerical results obtained by both methods are compared and presented graphically. It is observed that an increase in the permeability parameter causes decrease in the fluid velocity and an increase in the Jeffrey fluid parameter causes an enhancement in the fluid velocity. The significance of various pertinent parameters like Grashof number, Prandtl number, Eckert number and the plate velocity are explained through graphs.  

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