scholarly journals Periodic Energy Transport and Entropy Production in Quantum Electronics

Entropy ◽  
2016 ◽  
Vol 18 (11) ◽  
pp. 419 ◽  
Author(s):  
María Ludovico ◽  
Liliana Arrachea ◽  
Michael Moskalets ◽  
David Sánchez
Keyword(s):  
Quantum Electronics ◽  
Entropy Production ◽  
Energy Transport

scholarly journals Dynamics of energy transport and entropy production in ac-driven quantum electron systems

2016 ◽  
Vol 94 (3) ◽  
Author(s):  
María Florencia Ludovico ◽  
Michael Moskalets ◽  
David Sánchez ◽  
Liliana Arrachea
Keyword(s):  
Entropy Production ◽  
Energy Transport ◽  
Electron Systems ◽  
Quantum Electron

Entropy generation in MHD free convection of nanoliquid within a square open chamber with a solid body

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Sivaraj Chinnasamy ◽  
Vignesh E. ◽  
Mikhail Sheremet
Keyword(s):  
Entropy Production ◽  
Entropy Generation ◽  
Solid Body ◽  
Thermal Convection ◽  
Energy Transport ◽  
Entropy Generation Rate ◽  
Liquid Motion ◽  
Content Type ◽  
Aspect Ratios ◽  
Solid Block

Purpose The study aims to investigate magnetohydrodynamics thermal convection energy transference and entropy production in an open chamber saturated with ferrofluid having an isothermal solid block. Design/methodology/approach Analysis of thermal convection phenomenon was performed for an open chamber saturated with a nanofluid having an isothermal solid unit placed inside the cavity with various aspect ratios. The left border temperature is kept at Tc. An external cooled nanofluid of fixed temperature Tc penetrates into the domain from the right open border. The nanofluid circulation is Newtonian, incompressible, and laminar. The uniform magnetic field of strength B at the tilted angle of γ is applied. The finite volume technique is used to work out the non-linear equations of liquid motion and energy transport. For Rayleigh number (Ra=1e+7), numerical simulations were executed for varying the solid volume fractions of the nanofluid (ϕ = 0.01–0.04), the aspect ratios of a solid body (As = 0.25–4), the Hartmann number (Ha = 0–100), the magnetic influence inclination angle (γ = 0–π/2) and the non-dimensional temperature drop (Ω = 0.001–0.1) on the liquid motion, heat transference and entropy production. Findings Numerical outcomes are demonstrated by using isolines of temperature and stream function, profiles of mean Nusselt number and entropy generations. The results indicate that the entropy generation rate and mean Nu can be decreased with an increase in Ha. The inner solid block of As = 0.25 reflects the maximum heat transfer rate in comparison with other considered blocks. The addition of nano-sized particles results in a growth of energy transport and mean entropy generations. Originality/value An efficient computational technique has been developed to solve natural convection problem for an open chamber. The originality of this research is to scrutinize the convective transport and entropy production in an open domain with inner body. The outcomes would benefit scientists and engineers to become familiar with the investigation of convective energy transference and entropy generation in open chambers with inner bodies, and the way to predict the energy transference strength in the advanced engineering systems.

Thermal convection and entropy generation of ferrofluid in an enclosure containing a solid body

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Sivaraj Chinnasamy ◽  
S. Priyadharsini ◽  
Mikhail Sheremet
Keyword(s):  
Heat Transfer ◽  
Aspect Ratio ◽  
Entropy Production ◽  
Entropy Generation ◽  
Solid Body ◽  
Thermal Convection ◽  
Energy Transport ◽  
Content Type ◽  
Solid Block ◽  
Irreversibility Ratio

Purpose This study/paper aims to deal with thermal convection and entropy production of a ferrofluid in an enclosure having an isothermally warmed solid body placed inside. It should be noted that this research deals with a development of passive cooling system for the electronic devices. Design/methodology/approach The domain of interest is a square chamber of size L including a rectangular solid block of sizes l1 and l2. Thermal convection of ferrofluid (water–Fe3O4 nanosuspension) is analyzed within this enclosure. The solid body is considered to be isothermal with temperature Th and also its area is L2/9. The vertical borders are cold with temperature Tc and the horizontal boundaries are adiabatic. The flow driven by temperature gradient in the cavity is two-dimensional. The governing equations, formulated in dimensionless primitive variables with corresponding initial and boundary conditions, are worked out by using the finite volume technique with the semi-implicit method for pressure-linked equations algorithm on a uniformly staggered mesh. The influence of nanoparticles volume fraction, aspect ratio of the solid block and an irreversibility ratio on energy transport and flow patterns are examined for the Rayleigh number Ra = 107. Findings The results show that the nanoparticles concentration augments the thermal transmission and the entropy production increases also, while the augmentation of temperature difference results in a diminution of entropy production. Finally, lower aspect ratio has the significant impact on heat transfer, isotherms, streamlines and entropy. Originality/value An efficient numerical technique has been developed to solve this problem. The originality of this work is to analyze convective energy transport and entropy generation in a chamber with internal block. To the best of the authors’ knowledge, the effects of irreversibility ratio are scrutinized for the first time. The results would benefit scientists and engineers to become familiar with the analysis of convective heat transfer and entropy production in enclosures with internal isothermal blocks, and the way to predict the heat transfer rate in advanced technical systems, in industrial sectors including transportation, power generation, chemical sectors, electronics, etc.

Entropy Production During Laser Picosecond Heating of Copper

2002 ◽  
Vol 124 (3) ◽  
pp. 204-213 ◽  
Author(s):  
Bekir Sami Yilbas
Keyword(s):  
Entropy Production ◽  
Energy Transport ◽  
Pulse Heating ◽  
Short Pulse ◽  
Surface Region ◽  
Irreversible Processes ◽  
Heating Process ◽  
Theory Approach ◽  
Lattice Systems ◽  
Nonequilibrium Energy

Nonequilibrium energy transport taking place in the surface region of the metallic substrate due to laser short-pulse heating results in entropy production in electron and lattice systems. The entropy analysis gives insight into the irreversible processes taking place in this region during the laser short-pulse heating process. In the present study, entropy production during laser shortpulse heating of copper is considered. Equations governing the nonequilibrium energy transport are derived using an electron kinetic theory approach. The entropy equations due to electron and lattice systems and coupling of these systems are formulated. The governing equations of energy transport and entropy production are solved numerically. Two pulse shapes, namely step input intensity and exponential intensity, are employed in the analysis. It is found that entropy production due to coupling process attains higher values than those produced due to electron and lattice systems. The effect of pulse shape on the entropy production inside the substrate material is significant.

Energy, transport, and consumption in the Industrial Revolution

2019 ◽  
Vol 42 ◽  
Author(s):  
Joseph A. Tainter ◽  
Temis G. Taylor
Keyword(s):  
Mass Production ◽  
Industrial Revolution ◽  
Energy Transport ◽  
Underlying Assumption

Abstract We question Baumard's underlying assumption that humans have a propensity to innovate. Affordable transportation and energy underpinned the Industrial Revolution, making mass production/consumption possible. Although we cannot accept Baumard's thesis on the Industrial Revolution, it may help explain why complexity and innovation increase rapidly in the context of abundant energy.

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