MHD Flow of Cu-Al2O3/Water Hybrid Nanofluid in Porous Channel: Analysis of Entropy Generation

2017 ◽  
Vol 377 ◽  
pp. 42-61 ◽  
Author(s):  
Sanatan Das ◽  
Rabindra Nath Jana ◽  
Oluwole Daniel Makinde

In this investigation, a magnetohydrodynamic (MHD) flow of AlO /water nanofluid and Cu-AlO /water hybrid nanofluid through a porous channel is analyzed in the presence of a transverse magnetic field. An exact solution of the governing equations has been obtained in closed form. The entropy generation number and the Bejan number are also obtained. The influences of each of the governing parameters on velocity, temperature, entropy generation and Bejan number are displayed graphically and the physical aspects are discussed. In addition, a comparison of the heat transfer enhancement level due to the suspension of AlO and Cu nanoparticles in water as regular nanofluids and as hybrid Cu-AlO /water nanofluid is reported.

Energies ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2942 ◽  
Author(s):  
Ammar I. Alsabery ◽  
Ishak Hashim ◽  
Ahmad Hajjar ◽  
Mohammad Ghalambaz ◽  
Sohail Nadeem ◽  
...  

The present investigation addressed the entropy generation, fluid flow, and heat transfer regarding Cu-Al 2 O 3 -water hybrid nanofluids into a complex shape enclosure containing a hot-half partition were addressed. The sidewalls of the enclosure are made of wavy walls including cold isothermal temperature while the upper and lower surfaces remain insulated. The governing equations toward conservation of mass, momentum, and energy were introduced into the form of partial differential equations. The second law of thermodynamic was written for the friction and thermal entropy productions as a function of velocity and temperatures. The governing equations occurred molded into a non-dimensional pattern and explained through the finite element method. Outcomes were investigated for Cu-water, Al 2 O 3 -water, and Cu-Al 2 O 3 -water nanofluids to address the effect of using composite nanoparticles toward the flow and temperature patterns and entropy generation. Findings show that using hybrid nanofluid improves the Nusselt number compared to simple nanofluids. In the case of low Rayleigh numbers, such enhancement is more evident. Changing the geometrical aspects of the cavity induces different effects toward the entropy generation and Bejan number. Generally, the global entropy generation for Cu-Al 2 O 3 -water hybrid nanofluid takes places between the entropy generation values regarding Cu-water and Al 2 O 3 -water nanofluids.


2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
T. Chinyoka ◽  
O. D. Makinde

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.


Entropy ◽  
2019 ◽  
Vol 21 (4) ◽  
pp. 359 ◽  
Author(s):  
Arshad Khan ◽  
Faizan ul Karim ◽  
Ilyas Khan ◽  
Tawfeeq Alkanhal ◽  
Farhad Ali ◽  
...  

The current work will describe the entropy generation in an unsteady magnetohydrodynamic (MHD) flow with a combined influence of mass and heat transfer through a porous medium. It will consider the flow in the XY plane and the plate with isothermal and ramped wall temperature. The wall shear stress is also considered. The influences of different pertinent parameters on velocity, the Bejan number and on the total entropy generation number are reported graphically. Entropy generation in the fluid is controlled and reduced on the boundary by using wall shear stress. It is observed in this paper that by taking suitable values of pertinent parameters, the energy losses in the system can be minimized. These parameters are the Schmitt number, mass diffusion parameter, Prandtl number, Grashof number, magnetic parameter and modified Grashof number. These results will play an important role in the heat flow of uncertainty and must, therefore, be controlled and managed effectively.


Author(s):  
D. Srinivasacharya ◽  
K. Himabindu

AbstractThis article presents the effect of convective heating and velocity slip on flow generation of an incompressible micropolar fluid through a porous channel. The flow is induced by a constant axial pressure gradient applied in the flow direction. The non-linear governing equations are linearized using the quasilinearization technique and then solved by Chebyshev spectral collocation method. The numerical values of the velocity, microrotation and temperature are used to derive the corresponding entropy generation number and Bejan number within the porous channel. The influences of pertinent parameters on velocity, microrotation, temperature, entropy generation and Bejan number are discussed through graphs. It is observed that the convective heating tends to increase the entropy generation within the channel.


Author(s):  
Odelu Ojjela ◽  
Kesetti Ramesh ◽  
Samir K. Das

AbstractThe present article deals the entropy generation due to heat and mass transfer of an unsteady MHD flow of a Casson fluid squeezed between two parallel disks. The upper disk is taken to be impermeable and the lower one is porous. The flow field equations are reduced to non-linear ordinary differential equations by using similarity transformations and the resulting ODE problem is solved by shooting technique with Runge-Kutta 4thorder method. The effects of various non dimensional fluid and geometric parameters on the velocity components, temperature, concentration, entropy generation number, Bejan number, skin friction and Nusselt number are illustrated through graphs and tables. It is noticed that the temperature of the fluid is enhanced with Eckert number, whereas the concentration of the fluid decreased with Casson fluid parameter. The present study is applicable to nuclear engineering cooling systems, wire and blade coating, extrusion of polymer fluids, optical fibers, magnetohydrodynamics and optimization of chemical engineering processes.


2018 ◽  
Vol 7 (4.10) ◽  
pp. 863
Author(s):  
S. Sreenadh ◽  
V. Ramesh Babu ◽  
G. Gopi Krishna ◽  
S. R.Mishra ◽  
A. N.S.Srinivas

An investigation is made for analyzing the behavior of MHD flow phenomena of a non-Newtonian fluid over a non-linear radially stretching sheet by using numerical technique. Magnetic field is considered in normal direction to the stretching sheet. With use of similarity transformations, the pdes are transformed into odes. The solution of theses odes are performed by using fourth order Runge - Kutta method along with shooting technique. The significance of different physical parameters characterizes the flow phenomena are analyzed with the use of graphs. The Jeffrey parameter  and magnetic parameter  has significant effect on velocity and temperature distribution over a non-linear stretching sheet. It is noticed that, the higher magnetic parameter results the increase in entropy generation number where the opposite nature is noticed in the case of Bejan number.  


Author(s):  
Murat Havzali ◽  
Guven Komurgoz ◽  
Aytac Arikoglu ◽  
Haci Ibrahim Keser ◽  
Ibrahim Ozkol

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.


2015 ◽  
Vol 42 (1) ◽  
pp. 35-51 ◽  
Author(s):  
Vikas Kumar ◽  
Shalini Jain ◽  
Kalpna Sharma ◽  
Pooja Sharma

In the present paper, a theoretical analysis of entropy generation due to fully developed flow and heat transfer through a parallel plate channel partially filled with a porous medium under the effect of transverse magnetic field and radiation is presented. Both horizontal plates of the channel are kept at constant and equal temperature. An exact solution of governing equation for both porous and clear fluid regions has been obtained in closed form. The entropy generation number and the Bejan number are also calculated. The effects of various parameters such as magnetic field parameter, radiation parameter, Brinkman number, permeability parameter, ratios of viscosities and thermal conductivities are examined on velocity, temperature, entropy generation rate.


Micromachines ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 887
Author(s):  
Nabeela Parveen ◽  
Muhammad Awais ◽  
Saeed Ehsan Awan ◽  
Wasim Ullah Khan ◽  
Yigang He ◽  
...  

This research concerns the heat transfer and entropy generation analysis in the MHD axisymmetric flow of Al2O3-Cu/H2O hybrid nanofluid. The magnetic induction effect is considered for large magnetic Reynolds number. The influences of thermal radiations, viscous dissipation and convective temperature conditions over flow are studied. The problem is modeled using boundary layer theory, Maxwell’s equations and Fourier’s conduction law along with defined physical factors. Similarity transformations are utilized for model simplification which is analytically solved with the homotopy analysis method. The h-curves upto 20th order for solutions establishes the stability and convergence of the adopted computational method. Rheological impacts of involved parameters on flow variables and entropy generation number are demonstrated via graphs and tables. The study reveals that entropy in system of hybrid nanofluid affected by magnetic induction declines for [...]


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Tarek N. Abdelhameed

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.


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