scholarly journals Entropy Generation via Ohmic Heating and Hall Current in Peristaltically-Flowing Carreau Fluid

Entropy ◽  
2019 ◽  
Vol 21 (5) ◽  
pp. 529 ◽  
Author(s):  
Saima Noreen ◽  
Asif Abbas ◽  
Abid Hussanan
Keyword(s):  
Entropy Generation ◽  
Hall Current ◽  
Operating Temperature ◽  
Ohmic Heating ◽  
Bejan Number ◽  
Nonlinear Mathematical Model ◽  
Carreau Fluid ◽  
The Core ◽  
Entropy Generation Minimization ◽  
Confined Flow

The core objective of the present study is to examine entropy generation minimization via Hall current and Ohmic heating. Carreau fluid considerations interpret the unavailability of systems’ thermal energy (for mechanical work). The magneto hydrodynamic flow is in the channel, which is not symmetric. We have solved analytically the resulting nonlinear mathematical model. Moreover, physical exploration of important parameters on total entropy generation, temperature, and Bejan number is plotted and discussed. We observed that the generation of entropy takes place throughout the confined flow field y = W1 and y = W2 because of the viscous dissipation effect. In addition, reducing the operating temperature minimizes the entropy.

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.

Thermodynamic Analysis of Magnetohydrodynamic Third Grade Fluid Flow with Variable Properties

2021 ◽  
Vol 55 ◽  
pp. 28-46
Author(s):  
Kgomotshwana Frans Thosago ◽  
Lazarus Rundora ◽  
Samuel Olumide Adesanya
Keyword(s):  
Fluid Flow ◽  
Thermodynamic Analysis ◽  
Entropy Generation ◽  
Generation Rate ◽  
Third Grade ◽  
Entropy Generation Rate ◽  
Bejan Number ◽  
Third Grade Fluid ◽  
Entropy Generation Minimization ◽  
Grade Fluid

This article aims to computationally study entropy generation in a magnetohydrodynamic (MHD) third grade fluid flow in a horizontal channel with impermeable walls. The fluids viscosity and thermal conductivity are assumed to be dependent on temperature. The flow is driven by an applied uniform axial pressure gradient between infinite parallel plates and is considered to be incompressible, steady and fully developed. Adomian decomposition method (ADM) is used to obtain series solutions of the nonlinear governing equations. Thermodynamic analysis is done by computing the entropy generation rate and the irreversibility ratio (Bejan number). The effects of the various pertinent embedded parameters on the velocity field, temperature field, entropy generation rate and Bejan number are analysed through vivid graphical manipulations. The analysis shows that an appropriate combination of thermophysical parameters efficiently achieves entropy generation minimization in the thermomechanical system. The analysis shows that entropy generation minimization is achieved by increasing the magnetic field and the third grade material parameters, and therefore designs and processes incorporating MHD third grade fluid flow systems are far more likely to give optimum and efficient performance.

Circular Microchannel Heat Sink Optimization Using Entropy Generation Minimization Method

2020 ◽  
Vol 45 (4) ◽  
pp. 333-342
Author(s):  
Krishan Kumar ◽  
Rajan Kumar ◽  
Rabinder Singh Bharj
Keyword(s):  
Entropy Generation ◽  
Flow Rate ◽  
Heat Sink ◽  
Numerical Study ◽  
Bejan Number ◽  
Optimum Number ◽  
Microchannel Heat Sink ◽  
Heat Flow Rate ◽  
Entropy Generation Number ◽  
Entropy Generation Minimization

AbstractThe performance of the microchannel heat sink (MCHS) in electronic applications needs to be optimized corresponding to the number of channels (N). In this study optimization of the number of channels corresponding to the diameter of the microchannel ({D_{N}}) using an entropy generation minimization approach is achieved for the MCHS used in electronic applications. The numerical study is performed for constant total heat flow rate ({\dot{q}_{tot}}) and total mass flow rate ({\dot{m}_{tot}}). The results indicate that the dominance of frictional entropy generation ({S_{gen,Fr}}) increases with the reduction in diameter. However, the entropy generation due to heat transfer ({S_{gen,HT}}) decreases with the reduction in diameter. Therefore, the optimum diameter ({D^{\ast }}) is calculated corresponding to the minimum total entropy generation ({S_{gen,total}}) for the optimum number of channels ({N^{\ast }}). Furthermore, the entropy generation number ({N_{S}}) and Bejan number (Be) are also calculated.

scholarly journals Entropy generation and dissipative heat transfer analysis of mixed convective hydromagnetic flow of a Casson nanofluid with thermal radiation and Hall current

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
A. Sahoo ◽  
R. Nandkeolyar
Keyword(s):  
Temperature Distribution ◽  
Differential Equations ◽  
Ordinary Differential Equations ◽  
Entropy Generation ◽  
Ohmic Heating ◽  
Heat Transfer Analysis ◽  
Bejan Number ◽  
Casson Nanofluid ◽  
Highly Nonlinear ◽  
Physical Quantities

AbstractThe present article provides a detailed analysis of entropy generation on the unsteady three-dimensional incompressible and electrically conducting magnetohydrodynamic flow of a Casson nanofluid under the influence of mixed convection, radiation, viscous dissipation, Brownian motion, Ohmic heating, thermophoresis and heat generation. At first, similarity transformation is used to transform the governing nonlinear coupled partial differential equations into nonlinear coupled ordinary differential equations, and then the resulting highly nonlinear coupled ordinary differential equations are numerically solved by the utilization of spectral quasi-linearization method. Moreover, the effects of pertinent flow parameters on velocity distribution, temperature distribution, concentration distribution, entropy generation and Bejan number are depicted prominently through various graphs and tables. It can be analyzed from the graphs that the Casson parameter acts as an assisting parameter towards the temperature distribution in the absence of viscous and Joule dissipations, while it has an adverse effect on temperature under the impacts of viscous and Joule dissipations. On the contrary, entropy generation increases significantly for larger Brinkman number, diffusive variable and concentration ratio parameter, whereas the reverse effects of these parameters on Bejan number are examined. Apart from this, the numerical values of some physical quantities such as skin friction coefficients in x and z directions, local Nusselt number and Sherwood number for the variation of the values of pertinent parameters are displayed in tabular forms. A quadratic multiple regression analysis for these physical quantities has also been carried out to improve the present model’s effectiveness in various industrial and engineering areas. Furthermore, an appropriate agreement is obtained on comparing the present results with previously published results.

scholarly journals Second Law Analysis of Unsteady MHD Viscous Flow over a Horizontal Stretching Sheet Heated Non-Uniformly in the Presence of Ohmic Heating: Utilization of Gear-Generalized Differential Quadrature Method

Entropy ◽  
2019 ◽  
Vol 21 (3) ◽  
pp. 240 ◽  
Author(s):  
Muhammad Qasim ◽  
Muhammad Idrees Afridi ◽  
Abderrahim Wakif ◽  
T. Nguyen Thoi ◽  
Abid Hussanan
Keyword(s):  
Entropy Generation ◽  
Ohmic Heating ◽  
Differential Quadrature Method ◽  
Relaxation Method ◽  
Differential Quadrature ◽  
Bejan Number ◽  
Quadrature Method ◽  
Generalized Differential Quadrature Method ◽  
Special Cases ◽  
Generalized Differential

In this article, the entropy generation characteristics of a laminar unsteady MHD boundary layer flow are analysed numerically for an incompressible, electrically conducting and dissipative fluid. The Ohmic heating and energy dissipation effects are added to the energy equation. The modelled dimensional transport equations are altered into dimensionless self-similar partial differential equations (PDEs) through suitable transformations. The reduced momentum and energy equations are then worked out numerically by employing a new hybrid method called the Gear-Generalized Differential Quadrature Method (GGDQM). The obtained numerical results are incorporated in the calculation of the Bejan number and dimensionless entropy generation. Quantities of physical interest, like velocity, temperature, shear stress and heat transfer rate, are illustrated graphically as well as in tabular form. Impacts of involved parameters are examined and discussed thoroughly in this investigation. Exact and GGDQM solutions are compared for special cases of initial unsteady flow and final steady state flow. Furthermore, a good harmony is observed between the results of GGDQM and those given previously by the Spectral Relaxation Method (SRM), Spectral Quasilinearization Method (SQLM) and Spectral Perturbation Method (SPM).

scholarly journals Radiative MHD Nanofluid Flow over a Moving Thin Needle with Entropy Generation in a Porous Medium with Dust Particles and Hall Current

Entropy ◽  
2020 ◽  
Vol 22 (3) ◽  
pp. 354 ◽  
Author(s):  
Iskander Tlili ◽  
Muhammad Ramzan ◽  
Seifedine Kadry ◽  
Hyun-Woo Kim ◽  
Yunyoung Nam
Keyword(s):  
Porous Medium ◽  
Entropy Generation ◽  
Flow Model ◽  
Hall Current ◽  
Dust Particles ◽  
Bejan Number ◽  
Nonlinear Thermal Radiation ◽  
Nanofluid Flow ◽  
Forchheimer Number ◽  
Current Parameter

This paper investigated the behavior of the two-dimensional magnetohydrodynamics (MHD) nanofluid flow of water-based suspended carbon nanotubes (CNTs) with entropy generation and nonlinear thermal radiation in a Darcy–Forchheimer porous medium over a moving horizontal thin needle. The study also incorporated the effects of Hall current, magnetohydrodynamics, and viscous dissipation on dust particles. The said flow model was described using high order partial differential equations. An appropriate set of transformations was used to reduce the order of these equations. The reduced system was then solved by using a MATLAB tool bvp4c. The results obtained were compared with the existing literature, and excellent harmony was achieved in this regard. The results were presented using graphs and tables with coherent discussion. It was comprehended that Hall current parameter intensified the velocity profiles for both CNTs. Furthermore, it was perceived that the Bejan number boosted for higher values of Darcy–Forchheimer number.

Sign in / Sign up

Export Citation Format

Share Document