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Special Issue "Nature of Heat and Entropy: Fundamentals and Applications for Diverse and Sustainable Future"

A special issue of Entropy (ISSN 1099-4300). This special issue belongs to the section "Thermodynamics".

Deadline for manuscript submissions: closed (30 November 2018).

Special Issue Editor

Guest Editor
Prof. Dr. Milivoje M. Kostic

Department of Mechanical Engineering, Northern Illinois University, DeKalb, IL 60115, USA
Website 1 | Website 2 | E-Mail
Phone: +18154142021
Interests: fundamental laws of nature; thermodynamics and heat transfer fundamentals; the second law of thermodynamics and entropy; energy efficiency; conservation and sustainability; fluids-thermal-energy components and systems; nanotechnology and nanofluids

Special Issue Information

Dear Colleagues,

The fundamental laws of thermodynamics and comprehensive analysis and optimization are the most effective ways for improvement of efficiency and sustainability, and could lead to innovative developments. Heat, as transfer of thermal energy, is the unique and universal manifestation of all existence and all processes in nature. Thermodynamic Entropy, as thermal energy space, is associated with thermal energy only, and transferred with heat only, therefore, always generated with heat generation, accompanied with inevitable and irreversible dissipation of different kind of work potentials to thermal heat. Energy and environmental landscape could be substantially enhanced with innovations, improved efficiency, and diversification of energy sources, devices, and processes.

Therefore, advances in energy conversion and utilization technologies and increases in efficiency, including computerized control and management, contribute to energy efficiency and conservation, increase safety, and reduce related environmental pollution. In fact, per capita, energy use in the U.S. and other developed countries is being reduced in recent years. However, the increase in the world’s population and the development of many underdeveloped and fast-developing and very populated countries, like China, India, and others, will influence the continuous increase of world energy consumption and related impacts on the environment.

Let us not be fooled by lower oil prices due to unforeseen technological developments and an economic slowdown. If man-made global warming is debatable, two things are certain in the not-so-distant future: (1) the majority of the world population (poor now) and their living-standard expectations will increase substantially, and (2) fossil fuel economical reserves, particularly oil and natural gas, will decrease considerably. The difficulties that will face every nation and the world in meeting energy needs over the next several decades will be more challenging than what we anticipate now. Traditional solutions and approaches may not solve the global energy problem. New knowledge, new technology, and new living habits and expectations must be developed to address both, the quantity of energy needed to increase the standard of living world-wide, and to preserve sustainability and enhance the quality of our environment.

The fundamental laws of thermodynamics could unlock a brighter future. This Special Issue solicits diverse contributions to explore the most effective innovations by using the fundamental laws of thermodynamics, comprehensive analysis, and optimization.

Prof. Dr. Milivoje M. Kostic
Guest Editor

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All papers will be peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Entropy is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 1600 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • Heat
  • Entropy
  • Energy Efficiency
  • Energy Sustainability

Published Papers (6 papers)

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Research

Open AccessArticle
Cooling Effectiveness of a Data Center Room under Overhead Airflow via Entropy Generation Assessment in Transient Scenarios
Entropy 2019, 21(1), 98; https://doi.org/10.3390/e21010098
Received: 6 December 2018 / Revised: 12 January 2019 / Accepted: 18 January 2019 / Published: 21 January 2019
Cited by 1 | PDF Full-text (2336 KB) | HTML Full-text | XML Full-text
Abstract
Forecasting data center cooling demand remains a primary thermal management challenge in an increasingly larger global energy-consuming industry. This paper proposes a dynamic modeling approach to evaluate two different strategies for delivering cold air into a data center room. The common cooling method [...] Read more.
Forecasting data center cooling demand remains a primary thermal management challenge in an increasingly larger global energy-consuming industry. This paper proposes a dynamic modeling approach to evaluate two different strategies for delivering cold air into a data center room. The common cooling method provides air through perforated floor tiles by means of a centralized distribution system, hindering flow management at the aisle level. We propose an idealized system such that five overhead heat exchangers are located above the aisle and handle the entire server cooling demand. In one case, the overhead heat exchangers force the airflow downwards into the aisle (Overhead Downward Flow (ODF)); in the other case, the flow is forced to move upwards (Overhead Upward Flow (OUF)). A complete fluid dynamic, heat transfer, and thermodynamic analysis is proposed to model the system’s thermal performance under both steady state and transient conditions. Inside the servers and heat exchangers, the flow and heat transfer processes are modeled using a set of differential equations solved in MATLAB™ 2017a. This solution is coupled with ANSYS-Fluent™ 18, which computes the three-dimensional velocity, temperature, and turbulence on the Airside. The two approaches proposed (ODF and OUF) are evaluated and compared by estimating their cooling effectiveness and the local Entropy Generation. The latter allows identifying the zones within the room responsible for increasing the inefficiencies (irreversibilities) of the system. Both approaches demonstrated similar performance, with a small advantage shown by OUF. The results of this investigation demonstrated a promising approach of data center on-demand cooling scenarios. Full article
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Open AccessArticle
Desalination Processes’ Efficiency and Future Roadmap
Entropy 2019, 21(1), 84; https://doi.org/10.3390/e21010084
Received: 6 December 2018 / Revised: 29 December 2018 / Accepted: 14 January 2019 / Published: 18 January 2019
Cited by 1 | PDF Full-text (3363 KB) | HTML Full-text | XML Full-text
Abstract
For future sustainable seawater desalination, the importance of achieving better energy efficiency of the existing 19,500 commercial-scale desalination plants cannot be over emphasized. The major concern of the desalination industry is the inadequate approach to energy efficiency evaluation of diverse seawater desalination processes [...] Read more.
For future sustainable seawater desalination, the importance of achieving better energy efficiency of the existing 19,500 commercial-scale desalination plants cannot be over emphasized. The major concern of the desalination industry is the inadequate approach to energy efficiency evaluation of diverse seawater desalination processes by omitting the grade of energy supplied. These conventional approaches would suffice if the efficacy comparison were to be conducted for the same energy input processes. The misconception of considering all derived energies as equivalent in the desalination industry has severe economic and environmental consequences. In the realms of the energy and desalination system planners, serious judgmental errors in the process selection of green installations are made unconsciously as the efficacy data are either flawed or inaccurate. Inferior efficacy technologies’ implementation decisions were observed in many water-stressed countries that can burden a country’s economy immediately with higher unit energy cost as well as cause more undesirable environmental effects on the surroundings. In this article, a standard primary energy-based thermodynamic framework is presented that addresses energy efficacy fairly and accurately. It shows clearly that a thermally driven process consumes 2.5–3% of standard primary energy (SPE) when combined with power plants. A standard universal performance ratio-based evaluation method has been proposed that showed all desalination processes performance varies from 10–14% of the thermodynamic limit. To achieve 2030 sustainability goals, innovative processes are required to meet 25–30% of the thermodynamic limit. Full article
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Open AccessFeature PaperArticle
Nature of Heat and Thermal Energy: From Caloric to Carnot’s Reflections, to Entropy, Exergy, Entransy and Beyond
Entropy 2018, 20(8), 584; https://doi.org/10.3390/e20080584
Received: 11 July 2018 / Revised: 3 August 2018 / Accepted: 6 August 2018 / Published: 7 August 2018
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Abstract
The nature of thermal phenomena is still elusive and sometimes misconstrued. Starting from Lavoisier, who presumed that caloric as a weightless substance is conserved, to Sadi Carnot who erroneously assumed that work is extracted while caloric is conserved, to modern day researchers who [...] Read more.
The nature of thermal phenomena is still elusive and sometimes misconstrued. Starting from Lavoisier, who presumed that caloric as a weightless substance is conserved, to Sadi Carnot who erroneously assumed that work is extracted while caloric is conserved, to modern day researchers who argue that thermal energy is an indistinguishable part of internal energy, to the generalization of entropy and challengers of the Second Law of thermodynamics, the relevant thermal concepts are critically discussed here. Original reflections about the nature of thermo-mechanical energy transfer, classical and generalized entropy, exergy, and new entransy concept are reasoned and put in historical and contemporary contexts, with the objective of promoting further constructive debates and hopefully resolve some critical issues within the subtle thermal landscape. Full article
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Open AccessArticle
Statistics of Heat Transfer in Two-Dimensional Turbulent Rayleigh-Bénard Convection at Various Prandtl Number
Entropy 2018, 20(8), 582; https://doi.org/10.3390/e20080582
Received: 22 June 2018 / Revised: 5 August 2018 / Accepted: 6 August 2018 / Published: 7 August 2018
Cited by 1 | PDF Full-text (2385 KB) | HTML Full-text | XML Full-text
Abstract
Statistics of heat transfer in two-dimensional (2D) turbulent Rayleigh-Bénard (RB) convection for Pr=6,20,100 and 106 are investigated using the lattice Boltzmann method (LBM). Our results reveal that the large scale circulation is gradually broken up [...] Read more.
Statistics of heat transfer in two-dimensional (2D) turbulent Rayleigh-Bénard (RB) convection for Pr=6,20,100 and 106 are investigated using the lattice Boltzmann method (LBM). Our results reveal that the large scale circulation is gradually broken up into small scale structures plumes with the increase of Pr, the large scale circulation disappears with increasing Pr, and a great deal of smaller thermal plumes vertically rise and fall from the bottom to top walls. It is further indicated that vertical motion of various plumes gradually plays main role with increasing Pr. In addition, our analysis also shows that the thermal dissipation is distributed mainly in the position of high temperature gradient, the thermal dissipation rate εθ already increasingly plays a dominant position in the thermal transport, εu can have no effect with increase of Pr. The kinematic viscosity dissipation rate and the thermal dissipation rate gradually decrease with increasing Pr. The energy spectrum significantly decreases with the increase of Pr. A scope of linear scaling arises in the second order velocity structure functions, the temperature structure function and mixed structure function(temperature-velocity). The value of linear scaling and the 2nd-order velocity decrease with increasing Pr, which is qualitatively consistent with the theoretical predictions. Full article
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Open AccessArticle
Impact of Multi-Causal Transport Mechanisms in an Electrolyte Supported Planar SOFC with (ZrO2)x−1(Y2O3)x Electrolyte
Entropy 2018, 20(6), 469; https://doi.org/10.3390/e20060469
Received: 12 May 2018 / Revised: 7 June 2018 / Accepted: 14 June 2018 / Published: 16 June 2018
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Abstract
The calculation of the entropy production rate within an operational high temperature solid oxide fuel cell (SOFC) is necessary to design and improve heating and cooling strategies. However, due to a lack of information, most of the studies are limited to empirical relations, [...] Read more.
The calculation of the entropy production rate within an operational high temperature solid oxide fuel cell (SOFC) is necessary to design and improve heating and cooling strategies. However, due to a lack of information, most of the studies are limited to empirical relations, which are not in line with the more general approach given by non-equilibrium thermodynamics (NET). The SOFC 1D-model presented in this study is based on non-equilibrium thermodynamics and we parameterize it with experimental data and data from molecular dynamics (MD). The validation of the model shows that it can effectively describe the behavior of a SOFC at 1300 K. Moreover, we show that the highest entropy production is present in the electrolyte and the catalyst layers, and that the Peltier heat transfer is considerable for the calculation of the heat flux in the electrolyte and cannot be neglected. To our knowledge, this is the first validated model of a SOFC based on non-equilibrium thermodynamics and this study can be extended to analyze SOFCs with other solid oxide electrolytes, with perovskites electrolytes or even other electrochemical systems like solid oxide electrolysis cells (SOECs). Full article
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Open AccessArticle
Performance Features of a Stationary Stochastic Novikov Engine
Entropy 2018, 20(1), 52; https://doi.org/10.3390/e20010052
Received: 6 December 2017 / Revised: 8 January 2018 / Accepted: 8 January 2018 / Published: 12 January 2018
Cited by 2 | PDF Full-text (500 KB) | HTML Full-text | XML Full-text
Abstract
In this article a Novikov engine with fluctuating hot heat bath temperature is presented. Based on this model, the performance measure maximum expected power as well as the corresponding efficiency and entropy production rate is investigated for four different stationary distributions: continuous uniform, [...] Read more.
In this article a Novikov engine with fluctuating hot heat bath temperature is presented. Based on this model, the performance measure maximum expected power as well as the corresponding efficiency and entropy production rate is investigated for four different stationary distributions: continuous uniform, normal, triangle, quadratic, and Pareto. It is found that the performance measures increase monotonously with increasing expectation value and increasing standard deviation of the distributions. Additionally, we show that the distribution has only little influence on the performance measures for small standard deviations. For larger values of the standard deviation, the performance measures in the case of the Pareto distribution are significantly different compared to the other distributions. These observations are explained by a comparison of the Taylor expansions in terms of the distributions’ standard deviations. For the considered symmetric distributions, an extension of the well known Curzon–Ahlborn efficiency to a stochastic Novikov engine is given. Full article
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