scholarly journals Finite Element Simulations for Entropy Generation Measurement in Single Phase Flow of Water Based Nanofluid Filled in Square Cavity under Appliance of Inclined Magnetic field

2021 ◽  
Author(s):  
S. Bilal
Keyword(s):  
Magnetic Field ◽  
Finite Element ◽  
Entropy Generation ◽  
Flow Behavior ◽  
Vertical Direction ◽  
Convective Heating ◽  
Generation Process ◽  
Inclined Magnetic Field ◽  
Square Enclosure ◽  
Energy Equations

Abstract Current communication candidly explicates entropy generation process generated due to natural convective heating in square enclosure saturated with nanofluid. Water is used as base fluid and Cu particles are induced to depict enhancement in thermo physical characteristics. Natural convection in enclosure is produced by providing temperature difference on boundaries. Upper wall is provided uniform temperature while rest of walls are kept cold. Impermeability and non-slip conditions are imposed on all walls. Mathematical structuring of considered problem is manifested via continuity, momentum and energy equations under appliance of inclined magnetic field. Thermo physical properties of nanoparticles along with base liquids are used during mathematical structuring. Finite element procedure is adopted to elucidate flow features. Discretization of domain is done by applying hybrid meshing. Velocity and isothermal plots are drawn against concerning parameters. Comprehensive description of energy generation by measuring variation in magnetic, viscous, total and thermal irreversibility’s are also presented. Cut lines representing velocity field in horizontal and vertical direction are also drawn to predict flow behavior at different locations.

Free convection/radiation and entropy generation analyses for nanofluid of inclined square enclosure with uniform magnetic field

2020 ◽  
Vol 141 (1) ◽  
pp. 635-648 ◽  
Author(s):  
Yuanzhou Zheng ◽  
Somaye Yaghoubi ◽  
Amin Dezfulizadeh ◽  
Saeed Aghakhani ◽  
Arash Karimipour ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Free Convection ◽  
Entropy Generation ◽  
Uniform Magnetic Field ◽  
Square Enclosure

scholarly journals Effect of Inclined Magnetic Field on the Entropy Generation in an Annulus Filled with NEPCM Suspension

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Seyyed Masoud Seyyedi ◽  
M. Hashemi-Tilehnoee ◽  
M. Sharifpur
Keyword(s):  
Magnetic Field ◽  
Heat Transfer ◽  
Phase Change ◽  
Entropy Generation ◽  
Phase Change Materials ◽  
Transfer Problem ◽  
Mass Conservation ◽  
Melting Process ◽  
Industrial Applications ◽  
Inclined Magnetic Field

The encapsulation technique of phase change materials in the nanodimension is an innovative approach to improve the heat transfer capability and solve the issues of corrosion during the melting process. This new type of nanoparticle is suspended in base fluids call NEPCMs, nanoencapsulated phase change materials. The goal of this work is to analyze the impacts of pertinent parameters on the free convection and entropy generation in an elliptical-shaped enclosure filled with NEPCMs by considering the effect of an inclined magnetic field. To reach the goal, the governing equations (energy, momentum, and mass conservation) are solved numerically by CVFEM. Currently, to overcome the low heat transfer problem of phase change material, the NEPCM suspension is used for industrial applications. Validation of results shows that they are acceptable. The results reveal that the values of N u ave descend with ascending Ha while N gen has a maximum at Ha = 16 . Also, the value of N T , MF increases with ascending Ha . The values of N u ave and N gen depend on nondimensional fusion temperature where good performance is seen in the range of 0.35 < θ f < 0.6 . Also, Nu ave increases 19.9% and ECOP increases 28.8% whereas N gen descends 6.9% when ϕ ascends from 0 to 0.06 at θ f = 0.5 . Nu ave decreases 4.95% while N gen increases by 8.65% when Ste increases from 0.2 to 0.7 at θ f = 0.35 .

Numerical Flow Analysis of Electromagnetic Fluid Using GSMAC Finite-Element Method

2012 ◽  
Author(s):  
Kun Yang ◽  
Yoshitaka Saitoh ◽  
Hideki Kawai ◽  
Nobuyoshi Tsuzuki ◽  
Hiroshige Kikura ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Finite Element Method ◽  
Finite Element ◽  
Electric Field ◽  
Glass Furnace ◽  
Field Effect ◽  
Flow Behavior ◽  
Magnetic Field Effect ◽  
Heated Glass ◽  
Element Method

Numerical calculations for the cavity flow which simulates Joule-heated glass furnace were executed using GSMAC finite element method (GSMAC-FEM). The cavity consists of two main electrode plates on facing sides, two auxiliary electrode at the bottom and constant temperature wall on the top working as a heat sink. Magnetic field effect in Joule-heated glass furnace was verified by flow-electric-magnetic coupling analysis. When the calculation coupled with the flow and electric field was executed, unsteady down flows occurred from the top surface of the cavity. However, from the result of calculation coupled with flow, electric field and magnetic field, a large up flow appeared in the center of the cavity and permanently existed. Consequently, flow behavior including magnetic field was completely different from that excluding magnetic field effect. The results suggest that numerical analysis including magnetic field effect is recommended for accurate understanding of flow behavior in the Joule-heated glass furnaces. On the other hand, the data of velocity field, temperature field and magnetic field are also got by numerical simulation and compared with the result of Japan Atomic Energy Agency.

Nonhomogeneous model for conjugate mixed convection of nanofluid and entropy generation in an enclosure in presence of inclined magnetic field with Joule heating

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Subhasree Dutta ◽  
Somnath Bhattacharyya ◽  
Ioan Pop
Keyword(s):  
Magnetic Field ◽  
Heat Transfer ◽  
Mixed Convection ◽  
Entropy Generation ◽  
Joule Heating ◽  
Conjugate Heat Transfer ◽  
Inclined Magnetic Field ◽  
Content Type ◽  
The Impact ◽  
The Magnetic Field

Purpose This study aims to numerically analyse the impact of an inclined magnetic field and Joule heating on the conjugate heat transfer because of the mixed convection of an Al2O3–water nanofluid in a thick wall enclosure. Design/methodology/approach A horizontal temperature gradient together with the shear-driven Flow creates the mixed convection inside the enclosure. The nonhomogeneous model, in which the nanoparticles have a slip velocity because of thermophoresis and Brownian diffusion, is adopted in the present study. The thermal performance is evaluated by determining the entropy generation, which includes the contribution because of magnetic field. A control volume method over a staggered grid arrangement is adopted to compute the governing equations. Findings The Lorentz force created by the applied magnetic field has an adverse effect on the flow and thermal field, and consequently, the heat transfer and entropy generation attenuate because of the presence of magnetic force. The Joule heating enhances the fluid temperature but attenuates the heat transfer. The impact of the magnetic field diminishes as the angle of inclination of the magnetic field is increased, and it manifests as the volume fraction of nanoparticles is increased. Addition of nanoparticles enhances both the heat transfer and entropy generation compared to the clear fluid with enhancement in entropy generation higher than the rate by which the heat transfer augments. The average Bejan number and mixing-cup temperature are evaluated to analyse the thermodynamic characteristics of the nanofluid. Originality/value This literature survey suggests that the impact of an inclined magnetic field and Joule heating on conjugate heat transfer based on a two-phase model has not been addressed before. The impact of the relative slip velocity of nanoparticles diminishes as the magnetic field becomes stronger.

Magnetic field effect on the unsteady natural convection in a right-angle trapezoidal cavity filled with a nanofluid

2015 ◽  
Vol 25 (8) ◽  
pp. 1924-1946 ◽  
Author(s):  
N.S. Bondareva ◽  
M. A. Sheremet ◽  
I. Pop
Keyword(s):  
Magnetic Field ◽  
Natural Convection ◽  
Flow Behavior ◽  
Magnetic Field Effect ◽  
Dimensionless Time ◽  
Inclined Magnetic Field ◽  
Content Type ◽  
Industrial Sectors ◽  
Nuclear Systems ◽  
Unsteady Natural Convection

Purpose – Unsteady natural convection of water-based nanofluid within a right-angle trapezoidal cavity under the influence of a uniform inclined magnetic field using the mathematical nanofluid model proposed by Buongiorno is presented. The paper aims to discuss these issues. Design/methodology/approach – The left vertical and right inclined walls of the enclosure are kept at constant but different temperatures whereas the top and bottom horizontal walls are adiabatic. All boundaries are assumed to be impermeable to the base fluid and to nanoparticles. In order to study the behavior of the nanofluid, a non-homogeneous Buongiorno’s mathematical model is taken into account. The physical problems are represented mathematically by a set of partial differential equations along with the corresponding boundary conditions. By using an implicit finite difference scheme the dimensionless governing equations are numerically solved. Findings – The governing parameters are the Rayleigh, Hartmann and Lewis numbers along with the inclination angle of the magnetic field relative to the gravity vector, the aspect ratio and the dimensionless time. The effects of these parameters on the average Nusselt number along the hot wall, as well as on the developments of streamlines, isotherms and isoconcentrations are analyzed. The results show that key parameters have substantial effects on the flow, heat and mass transfer characteristics. Originality/value – The present results are new and original for the heat transfer and fluid flow in a right-angle trapezoidal cavity under the influence of a uniform inclined magnetic field using the mathematical nanofluid model proposed by Buongiorno. The results would benefit scientists and engineers to become familiar with the flow behavior of such nanofluids, and the way to predict the properties of this flow for possibility of using nanofluids in advanced nuclear systems, in industrial sectors including transportation, power generation, chemical sectors, ventilation, air-conditioning, etc.

Entropy analysis of Poiseuille nanofluid flow in a porous channel with slip and convective boundary conditions under magnetic field

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
S. Das ◽  
S. Chakraborty ◽  
R. N. Jana
Keyword(s):  
Magnetic Field ◽  
Entropy Generation ◽  
Poiseuille Flow ◽  
Magnetic Parameter ◽  
Generation Rate ◽  
Entropy Generation Rate ◽  
Convective Heating ◽  
Bejan Number ◽  
Content Type ◽  
Hydrodynamic Slip

Purpose This study aims to expose the flow phenomena and entropy generation during a; magnetohydrodynamic (MHD) Poiseuille flow of water-based nanofluids (NFs) in a porous channel subject to hydrodynamic slip and convective heating boundary conditions. The flow caused by the uniform pressure; gradient between infinite parallel plates is considered steady and fully developed. The nanoparticles; namely, copper, alumina and titanium oxide are taken with pure water as the base fluid. Viscous dissipation and Joule heating impacts are also incorporated in this investigation. Design/methodology/approach The reduced governing equations are solved analytically in closed form. The physical insights of noteworthy parameters on the important flow quantities are demonstrated through graphs and analyzed elaborately. The thermodynamic analysis is performed by calculating entropy generation; rate and Bejan number. A graphical comparison between solutions corresponding to NFs and regular fluid in the channel is also provided. Findings The analysis of the results divulges that entropy generation minimization can be achieved by an appropriate combination of the geometrical and physical parameters of thermomechanical systems. It is reported that ascent in magnetic parameter number declines the velocity profiles, while the inverse pattern is witnessed with augmentation in hydrodynamic slip parameters. The temperature dissemination declines with the growth of Biot numbers. It is perceived that the entropy generation rate lessens with an upgrade in magnetic parameter, whereas the reverse trend of Bejan number is perceived with expansion in magnetic parameter and Biot number. The important contribution of the result is that the entropy generation rate is controlled with an appropriate composition of thermo-physical parameter values. Moreover, in the presence of a magnetic field and suction/injection at the channel walls, the shear stresses at the channel walls are reduced about two times. Practical implications In various industrial applications, minimizing entropy generation plays a significant role. Miniaturization of entropy is the utilization of the energy of thermal devices such as micro heat exchangers, micromixers, micropumps and cooling microelectromechanical devices. Originality/value An attentive review of the literature discloses that quite a few studies have been conducted on entropy generation analysis of a fully developed MHD Poiseuille flow of NFs through a permeable channel subject to the velocity slip and convective heating conditions at the walls.

Sign in / Sign up

Export Citation Format

Share Document