Entropy Analysis of the Nonlinear Convective Flow of a Jeffrey Fluid over an Inclined Sheet with Variable Electrical Conductivity and Thermal Conductivity

Author(s):  
Jacob A. Gbadeyan ◽  
Joseph O. Akinremi

A steady two-dimensional nonlinear convective flow of a viscous, incompressible, electrically conducting, and non-Newtonian Jeffrey fluid over an inclined stretching sheet with convective boundary conditions and entropy generation is studied under the influence of transverse magnetic field, electrical conductivity and thermal conductivity. The thermal conductivity and electrical conductivity are temperature dependent functions. The governing continuity, momentum and energy equations are transformed to ordinary differential equations (ODEs) using appropriate similarity variables. The resulting coupled ODEs and the corresponding boundary conditions, are solved numerically using Runge-Kutta fourth order method and shooting technique. The velocity, entropy generation rate, temperature and Bejan distributions are presented graphically and discussed. The numerical values of the skin-friction and Nusselt number are obtained and also discussed for various thermophysical parameters through a Table. Furthermore, a comparison with earlier work done with limiting case was carried out and found to be in excellent agreement.

2004 ◽  
Vol 82 (6) ◽  
pp. 447-458 ◽  
Author(s):  
A A Afify

The effects of radiation and chemical reactions, in the presence of a transverse magnetic field, on free convective flow and mass transfer of an optically dense viscous, incompressible, and electrically conducting fluid past a vertical isothermal cone surface are investigated. The nonlinear boundary-layer equations with the boundary conditions are transferred by a similarity transformation into a system of nonlinear ordinary differential equations with the appropriate boundary conditions. Furthermore, the similarity equations are solved numerically by using a fourth-order Runge–Kutta scheme with the shooting method. Numerical results for the skin-friction coefficient, the local Nusselt number, the local Sherwood number are given; as well, the velocity, temperature, and concentration profiles are presented for a Prandtl number of 0.7, the chemical-reaction parameter, the order of the reaction, the radiation parameter, the Schmidt number, the magnetic parameter, and the surface temperature parameter. PACS No.: 47.70.Fw


2019 ◽  
Vol 26 ◽  
pp. 62-83
Author(s):  
Tunde Abdulkadir Yusuf ◽  
Jacob Abiodun Gbadeyan

In this study the effect of entropy generation on two dimensional magnetohydrodynamic (MHD) flow of a Maxwell fluid over an inclined stretching sheet embedded in a non-Darcian porous medium with velocity slip and convective boundary condition is investigated. Darcy-Forchheimer based model was employed to describe the flow in the porous medium. The non-linear thermal radiation is also taken into account. Similarity transformation is used to convert the non-linear partial differential equations to a system of non-linear ordinary differential equations. The resulting transformed equations are then solved using the Homotopy analysis method (HAM). Influence of various physical parameters on the dimensionless velocity profile, temperature profile and entropy generation are shown graphically and discussed in detail while the effects of these physical parameters on velocity gradient and temperature gradient are aided with the help of Table. Furthermore, comparison of some limiting cases of this model was made with existing results. The results obtained are found to be in good agreement with previously published results. Moreover, increase in local inertial coefficient parameter is found to decrease the entropy generation rate.


Author(s):  
BJ Gireesha ◽  
CT Srinivasa ◽  
NS Shashikumar ◽  
Madhu Macha ◽  
JK Singh ◽  
...  

The combined effects of the magnetic field, suction/injection, and convective boundary condition on heat transfer and entropy generation in an electrically conducting Casson fluid flow through an inclined porous microchannel are scrutinized. The temperature-dependent heat source is also accounted. Numerical simulation for the modelled problem is presented via Runge–Kutta–Felhberg-based shooting technique. Special attention is given to analyze the impact of involved parameters on the profiles of velocity [Formula: see text], temperature [Formula: see text], entropy generation [Formula: see text], and Bejan number [Formula: see text]. It is established that entropy generation rate decreases at the walls with an increase in Hartmann number [Formula: see text], while it increases at the center region of the microchannel.


2012 ◽  
Vol 67 (8-9) ◽  
pp. 517-524 ◽  
Author(s):  
Ahmed Alsaedi ◽  
Zahid Iqbal ◽  
Meraj Mustafa ◽  
Tasawar Hayat

The two-dimensional magnetohydrodynamic (MHD) flow of a Jeffrey fluid is investigated in this paper. The characteristics of heat and mass transfer with chemical reaction have also been analyzed. Convective boundary conditions have been invoked for the thermal boundary layer problem. Exact similarity solutions for flow, temperature, and concentration are derived. Interpretation to the embedded parameters is assigned through graphical results for dimensionless velocity, temperature, concentration, skin friction coefficient, and surface heat and mass transfer. The results indicate an increase in the velocity and the boundary layer thickness by increasing the rheological parameter of the Jeffrey fluid. An intensification in the chemical reaction leads to a thinner concentration boundary layer.


Symmetry ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 102 ◽  
Author(s):  
Arshad Riaz ◽  
Muhammad Mubashir Bhatti ◽  
Rahmat Ellahi ◽  
Ahmed Zeeshan ◽  
Sadiq M. Sait

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.


Entropy ◽  
2020 ◽  
Vol 22 (6) ◽  
pp. 672
Author(s):  
Yikun Wei ◽  
Pingping Shen ◽  
Zhengdao Wang ◽  
Hong Liang ◽  
Yuehong Qian

Time evolution features of kinetic and thermal entropy generation rates in turbulent Rayleigh-Bénard (RB) convection with mixed insulating and conducting boundary conditions at Ra = 109 are numerically investigated using the lattice Boltzmann method. The state of flow gradually develops from laminar flow to full turbulent thermal convection motion, and further evolves from full turbulent thermal convection to dissipation flow in the process of turbulent energy transfer. It was seen that the viscous, thermal, and total entropy generation rates gradually increase in wide range of t/τ < 32 with temporal evolution. However, the viscous, thermal, and total entropy generation rates evidently decrease at time t/τ = 64 compared to that of early time. The probability density function distributions, spatial-temporal features of the viscous, thermal, and total entropy generation rates in the closed system provide significant physical insight into the process of the energy injection, the kinetic energy, the kinetic energy transfer, the thermal energy transfer, the viscous dissipated flow and thermal dissipation.


Author(s):  
NS Shashikumar ◽  
K. Thriveni ◽  
Macha Madhu ◽  
B. Mahanthesh ◽  
BJ Gireesha ◽  
...  

The main theme of the current work is to investigate the flow and heat transport characteristics of non-Newtonian Williamson fluid in an inclined micro-channel along with entropy generation analysis. The significance of the thermal radiation, convective boundary condition, and multiple slip effects is explored. The entropy generation of the system has been analyzed by adopting the 2nd law of thermodynamics. The rheological expressions of the Williamson fluid model are also taken into account. The nonlinear system is tackled by using the finite element method. An appropriate comparison has been made with previously published results in the literature as a limiting case of the considered problem. The comparison confirmed an excellent agreement. Detailed discussion of the significance of effective parameters on Bejan number, entropy generation rate, temperature and velocity is presented through graphs. The numerical results portray that the entropy generation and Bejan number have escalating behavior to the higher value of angle of inclination. Furthermore, the Bejan number changing its behavior at two points for different values of Reynolds’ number.


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