
显示样式: 排序: IF: - GO 导出
-
Thermal Stress Development in Low Dimensional Silicon Film: An Analytical Approach J. Non Equilib. Thermodyn. (IF 2.157) Pub Date : 2021-01-07 Bekir Sami Yilbas; R. S. M. Alassar; Ahmad Y. Al-Dweik
Thermal excitation of the low dimensional silicon film is introduced and an analytical approach is adopted for the solution of the transport equation. In the analysis, the phonon radiative transport equation is converted into an integral form of the Fredholm equation of the second kind. The analytical approach is extended to include the formulation of thermal stresses for the following cases: (i) stress-free
-
Frontmatter J. Non Equilib. Thermodyn. (IF 2.157) Pub Date : 2021-01-05
Journal Name: Journal of Non-Equilibrium Thermodynamics Volume: 46 Issue: 1 Pages: I-IV
-
Polydisperse Colloids Two-Moment Diffusion Model Through Irreversible Thermodynamics Considerations J. Non Equilib. Thermodyn. (IF 2.157) Pub Date : 2020-11-18 Mohamed Bouzghaia; Ferhat Souidi; Zakaria Larbi
This study deals with the problem of diffusion for polydisperse colloids. The resolution of this complex problem usually requires computationally expensive numerical models. By considering the number of colloidal particles and their mass as independent variables, the equations of state for a dilute polydisperse colloid are derived on a statistical mechanics basis. Irreversible thermodynamics is then
-
The Ideal Gas in Slow Time J. Non Equilib. Thermodyn. (IF 2.157) Pub Date : 2020-11-18 Christopher Essex; Bjarne Andresen
We continue our exploration of thermodynamics at long observational timescales, “slow time,” by including turbulent dynamics leading to a condition of fluctuating local equilibrium. Averaging these fluctuations in wind speed and temperature results in a velocity distribution with heavy tails which, however, are necessarily truncated at some large molecular speed preserving all moments of the velocity
-
Modeling of irreversible two-stage combined thermal Brownian refrigerators and their optimal performance J. Non Equilib. Thermodyn. (IF 2.157) Pub Date : 2020-12-11 Congzheng Qi; Zemin Ding; Lingen Chen; Yanlin Ge; Huijun Feng
This paper establishes a model of an irreversible two-stage combined thermal Brownian refrigerator with an intermediate heat reservoir by combining finite time thermodynamics with non-equilibrium thermodynamics. The model is composed of two irreversible thermal Brownian refrigerators working in series. The combined thermal Brownian refrigerator works among three constant temperature heat reservoirs
-
Effect of Copper Electrode Geometry on Electrofreezing of the Phase-Change Material CaCl2·6H2O J. Non Equilib. Thermodyn. (IF 2.157) Pub Date : 2020-12-11 Ahmad Swandi; Annisa Rahman; Risky Afandi Putri; Radhiah Anggraini; Daniel Kurnia; Surjamanto Wonorahardjo; Inge Magdalena Sutjahja
The development of effective active thermal energy storage systems requires an understanding of how electrode geometry affects the electrofreezing process. This study aimed to observe the nucleation behavior of an inorganic phase-change material, CaCl2·6H2O, using a DC electric field and various copper electrode geometries. The effects of both the electrode diameter (d=0.5 and 0.7 mm) and the tip shape
-
Performance Optimization for a Multielement Thermoelectric Refrigerator with Linear Phenomenological Heat Transfer Law J. Non Equilib. Thermodyn. (IF 2.157) Pub Date : 2020-12-11 Lingen Chen; Fankai Meng; Yanlin Ge; Huijun Feng
A model of a multielement thermoelectric refrigerator with another linear heat transfer law, the linear phenomenological heat transfer law Q∝Δ(1/T), is established. The refrigerating capacity and coefficient of performance (COP) are analyzed and optimized. The junction temperature solution equations are derived. The optimum electrical currents and thermal conductance allocation are discussed. The influences
-
Non-Equilibrium Thermodynamic Analysis of Flash Evaporation Process in Vacuum Ice Making J. Non Equilib. Thermodyn. (IF 2.157) Pub Date : 2020-11-10 Lingeng Zou; Xuelai Zhang
Traditional equilibrium thermodynamics can only solve a few equilibrium processes composed of continuous stable equilibrium states. However, the vacuum flash evaporation process is a typical unsteady process. The study of non-equilibrium thermodynamics of the two-phase flow model is helpful to improve our understanding of the basic law of the flash evaporation process. Based on the theory of non-equilibrium
-
Modeling of Separation in a Binary Mixture with Negative Soret Effect in a Cylindrical Thermogravitational Column J. Non Equilib. Thermodyn. (IF 2.157) Pub Date : 2020-10-20 Sofia V. Kozlova; Ilya I. Ryzhkov; M. Mounir Bou-Ali
A numerical simulation of convective instability of a binary fluid with negative Soret effect in a cylindrical thermogravitational column is performed. The general problem statement, including equations of motion and heat/mass transfer with boundary conditions, are written in cylindrical coordinates. This is implemented in order to take into account the impact of the column geometry on the separation
-
Open-Circuit Voltage Comes from Non-Equilibrium Thermodynamics J. Non Equilib. Thermodyn. (IF 2.157) Pub Date : 2020-10-16 Diego del Olmo; Michal Pavelka; Juraj Kosek
Originally derived by Walther Nernst more than a century ago, the Nernst equation for the open-circuit voltage is a cornerstone in the analysis of electrochemical systems. Unfortunately, the assumptions behind its derivation are often overlooked in the literature, leading to incorrect forms of the equation when applied to complex systems (for example, those with ion-exchange membranes or involving
-
A Framework of Nonequilibrium Statistical Mechanics. II. Coarse-Graining J. Non Equilib. Thermodyn. (IF 2.157) Pub Date : 2020-10-07 Alberto Montefusco; Mark A. Peletier; Hans Christian Öttinger
For a given thermodynamic system, and a given choice of coarse-grained state variables, the knowledge of a force-flux constitutive law is the basis for any nonequilibrium modeling. In the first paper of this series we established how, by a generalization of the classical fluctuation-dissipation theorem (FDT), the structure of a constitutive law is directly related to the distribution of the fluctuations
-
Frontmatter J. Non Equilib. Thermodyn. (IF 2.157) Pub Date : 2020-09-23
Journal Name: Journal of Non-Equilibrium Thermodynamics Volume: 45 Issue: 4 Pages: I-IV
-
Three-Dimensional Ballistic-Diffusive Heat Transport in Silicon: Transient Response and Thermal Conductivity J. Non Equilib. Thermodyn. (IF 2.157) Pub Date : 2020-08-19 Saad Bin Mansoor; Bekir S. Yilbas
Phonons are the main contributors to thermal energy transfer in thin films. The size dependence of the thermal transport characteristics alters the film properties such as thermal conductivity. Hence, in the present study, three-dimensional, transient phonon transport in dielectric material is studied through the Equation of Phonon Radiative Transport (EPRT) to assess the size dependence of thermal
-
Application of Irreversible Thermodynamics to Diffusion in Solids with Internal Surfaces J. Non Equilib. Thermodyn. (IF 2.157) Pub Date : 2020-07-17 Anna G. Knyazeva
Two types of additional variables were included in the set of state variables and were used for a thermodynamic description of diffusion in an ordinary thermodynamic system. Vacancies are included in the mass balance. Internal surfaces are massless but are characterized by some energy, which is included in the energy balance of the thermodynamic system. Fluxes of components, vacancies, and surfaces
-
Membrane Transport in Concentration Polarization Conditions: Evaluation of S-Entropy Production for Ternary Non-Electrolyte Solutions J. Non Equilib. Thermodyn. (IF 2.157) Pub Date : 2020-08-25 Andrzej Ślęzak; Sławomir Grzegorczyn; Kornelia M. Batko; Wiesław Pilis; Robert Biczak
A model of the S-entropy production in a system with a membrane which separates non-electrolyte aqueous solutions was presented. The differences between fluxes in non-homogeneous and homogeneous conditions for volume and solute fluxes, respectively, are non-linear functions of the glucose osmotic pressure difference (OPD) in ranges dependent on the initial ethanol OPD. A decrease of ethanol OPD causes
-
Thermodynamic Theory of Diffusion and Thermodiffusion Coefficients in Multicomponent Mixtures J. Non Equilib. Thermodyn. (IF 2.157) Pub Date : 2020-07-16 Alexander A. Shapiro
Transport coefficients (like diffusion and thermodiffusion) are the key parameters to be studied in non-equilibrium thermodynamics. For practical applications, it is important to predict them based on the thermodynamic parameters of a mixture under study: pressure, temperature, composition, and thermodynamic functions, like enthalpies or chemical potentials. The current study develops a thermodynamic
-
Circular Microchannel Heat Sink Optimization Using Entropy Generation Minimization Method J. Non Equilib. Thermodyn. (IF 2.157) Pub Date : 2020-08-06 Krishan Kumar; Rajan Kumar; Rabinder Singh Bharj
The performance of the microchannel heat sink (MCHS) in electronic applications needs to be optimized corresponding to the number of channels (N). In this study optimization of the number of channels corresponding to the diameter of the microchannel (DN) using an entropy generation minimization approach is achieved for the MCHS used in electronic applications. The numerical study is performed for constant
-
Exergy-Based Ecological Optimization of an Irreversible Quantum Carnot Heat Pump with Spin-1/2 Systems J. Non Equilib. Thermodyn. (IF 2.157) Pub Date : 2020-09-08 Xiaowei Liu; Lingen Chen; Yanlin Ge; Huijun Feng; Feng Wu; Giulio Lorenzini
Based on an irreversible quantum Carnot heat pump model in which spin-1/2 systems are used as working substance, an exergy-based ecological function and some other important parameters of the model heat pump are derived. Numerical examples are provided to investigate its ecological performance characteristics. The influences of various irreversibility factors on the ecological performance are discussed
-
A Framework of Nonequilibrium Statistical Mechanics. I. Role and Types of Fluctuations J. Non Equilib. Thermodyn. (IF 2.157) Pub Date : 2020-09-03 Hans Christian Öttinger; Mark A. Peletier; Alberto Montefusco
Understanding the fluctuations by which phenomenological evolution equations with thermodynamic structure can be enhanced is the key to a general framework of nonequilibrium statistical mechanics. These fluctuations provide an idealized representation of microscopic details. We consider fluctuation-enhanced equations associated with Markov processes and elaborate the general recipes for evaluating
-
Natural Convection Around a Locally Heated Circular Cylinder Placed in a Rectangular Enclosure J. Non Equilib. Thermodyn. (IF 2.157) Pub Date : 2020-09-02 Nepal Chandra Roy; Md. Anwar Hossain; Rama Subba Reddy Gorla; Sadia Siddiqa
Natural convective flow and heat transfer around a locally heated circular cylinder kept in a rectangular enclosure are investigated. At first, a problem valid for a rectangular domain is formulated and then an analytical coordinate transformation is introduced to map the rectangular domain to the physical domain considered here. Based on the coordinate transformation, a set of governing equations
-
Entropy Generation in Magnetized Blood Flow Through a Finite Wavy Channel Under Slip Conditions J. Non Equilib. Thermodyn. (IF 2.157) Pub Date : 2020-07-02 Lijun Zhang; Muhammad Mubashir Bhatti; Efstathios E. Michaelides
This study deals with the entropy generation in magnetized blood flow through a channel. The blood is modeled as a non-Newtonian fluid that circulates by a uniform peristaltic wave with slip at the boundaries. An inertia free flow is considered using an approximation of the long-wavelength peristaltic wave. The governing equations of the flow are formulated and numerically solved using computational
-
Effect of Nanofluid on Heat Transfer Enhancement for Mixed Convection Flow Over a Corrugated Surface J. Non Equilib. Thermodyn. (IF 2.157) Pub Date : 2020-07-01 Nepal Chandra Roy; Sadia Siddiqa
A mathematical model for mixed convection flow of a nanofluid along a vertical wavy surface has been studied. Numerical results reveal the effects of the volume fraction of nanoparticles, the axial distribution, the Richardson number, and the amplitude/wavelength ratio on the heat transfer of Al2O3-water nanofluid. By increasing the volume fraction of nanoparticles, the local Nusselt number and the
-
Frontmatter J. Non Equilib. Thermodyn. (IF 2.157) Pub Date : 2020-06-26
Journal Name: Journal of Non-Equilibrium Thermodynamics Volume: 45 Issue: 3 Pages: I-IV
-
Internal Variable Theory Formulated by One Extended Potential Function J. Non Equilib. Thermodyn. (IF 2.157) Pub Date : 2020-06-03 Qiang Yang; Zhuofu Tao; Yaoru Liu
In the kinetic rate laws of internal variables, it is usually assumed that the rates of internal variables depend on the conjugate forces of the internal variables and the state variables. The dependence on the conjugate force has been fully addressed around flow potential functions. The kinetic rate laws can be formulated with two potential functions, the free energy function and the flow potential
-
Endoreversible Otto Engines at Maximal Power J. Non Equilib. Thermodyn. (IF 2.157) Pub Date : 2020-05-30 Zackary Smith; Priyo S. Pal; Sebastian Deffner
Despite its idealizations, thermodynamics has proven its power as a predictive theory for practical applications. In particular, the Curzon–Ahlborn efficiency provides a benchmark for any real engine operating at maximal power. Here we further develop the analysis of endoreversible Otto engines. For a generic class of working mediums, whose internal energy is proportional to some power of the temperature
-
Two Temperature Extension of Phonon Hydrodynamics J. Non Equilib. Thermodyn. (IF 2.157) Pub Date : 2020-06-03 Bing-Yang Cao; Miroslav Grmela; Zeng-Yuan Guo; Yu-Chao Hua; Ben-Dian Nie
Phonon hydrodynamics uses the fields of the total energy and the heat flux as state variables. We extend it by promoting the microscopic internal energy field into the status of an extra independent state variable. The governing equations of both the phonon and the extended (two temperature) phonon hydrodynamics are formulated as particular realizations of the abstract GENERIC equation. Such unified
-
Energetic Optimization Considering a Generalization of the Ecological Criterion in Traditional Simple-Cycle and Combined-Cycle Power Plants J. Non Equilib. Thermodyn. (IF 2.157) Pub Date : 2020-05-30 Sergio Levario-Medina; Gabriel Valencia-Ortega; Marco Antonio Barranco-Jiménez
The fundamental issue in the energetic performance of power plants, working both as traditional fuel engines and as combined-cycle turbines (gas-steam), lies in quantifying the internal irreversibilities which are associated with the working substance operating in cycles. The purpose of several irreversible energy converter models is to find objective thermodynamic functions that determine operation
-
Oxytactic Microorganisms and Thermo-Bioconvection Nanofluid Flow Over a Porous Riga Plate with Darcy–Brinkman–Forchheimer Medium J. Non Equilib. Thermodyn. (IF 2.157) Pub Date : 2020-05-08 Lijun Zhang; Muhammad Mubashir Bhatti; Rahmat Ellahi; Efstathios E. Michaelides
The aim of this paper is to analyze the behavior of oxytactic microorganisms and thermo-bioconvection nanofluid flow through a Riga plate with a Darcy–Brinkman–Forchheimer porous medium. The Riga plate is composed of electrodes and magnets that are placed on a plane. The fluid is electrically conducting, and the Lorentz force evolves exponentially along the vertical direction. The governing equations
-
A Theoretical Study of the Temperature Gradient Effect on the Soret Coefficient in n-Pentane/n-Decane Mixtures Using Non-Equilibrium Molecular Dynamics J. Non Equilib. Thermodyn. (IF 2.157) Pub Date : 2020-06-24 Xiaoyu Chen; Ruquan Liang; Yong Wang; Ziqi Xia; Lichun Wu; Yang Liang; Gan Cui
The effect of the temperature gradient on the Soret coefficient in n-pentane/n-decane (n-C5/n-C10) mixtures was investigated using non-equilibrium molecular dynamics (NEMD) with the heat exchange (eHEX) algorithm. n-Pentane/n-decane mixtures with three different compositions (0.25, 0.5, and 0.75 mole fractions, respectively) and the TraPPE-UA force field were used in computing the Soret coefficient
-
Frontmatter J. Non Equilib. Thermodyn. (IF 2.157) Pub Date : 2020-04-26
Journal Name: Journal of Non-Equilibrium Thermodynamics Volume: 45 Issue: 2 Pages: I-IV
-
Optimal Performance Regions of Feynman’s Ratchet Engine with Different Optimization Criteria J. Non Equilib. Thermodyn. (IF 2.157) Pub Date : 2020-04-26 Zemin Ding; Yanlin Ge; Lingen Chen; Huijun Feng; Shaojun Xia
Thermodynamic performance analysis of microscopic Feynman’s engine has always been a hot topic, since it can reveal the operating mechanism of the system and give out the suggestions of performance improvement. The present work explores the optimal performance regions of the ratchet operating, respectively, as heat engine and refrigerator. The major purpose is to obtain the optimal performance bunds
-
Simultaneous Impacts of Fe3O4{\text{Fe}_{3}}{\text{O}_{4}} Particles and Thermal Radiation on Natural Convection of Non-Newtonian Flow Between Two Vertical Flat Plates Using ADM J. Non Equilib. Thermodyn. (IF 2.157) Pub Date : 2020-04-26 Ameur Gabli; Mohamed Kezzar; Lilia Zighed; Mohamed Rafik Sari; Ismail Tabet
The main aim of this research work is to show the simultaneous effects of ferro-particles (Fe3O4) and thermal radiation on the natural convection of non-Newtonian nanofluid flow between two vertical flat plates. The studied nanofluid is created by dispersing ferro-particles (Fe3O4) in sodium alginate (SA), which is considered as a non-Newtonian base fluid. Resolution of the resulting set of coupled
-
Evaluation of Irreversibility and Optimal Organization of an Integrated Multi-Stream Heat Exchange System J. Non Equilib. Thermodyn. (IF 2.157) Pub Date : 2020-04-26 Sergey Yurevish Boykov; Biarne Andresen; Andrey Aleksandrobish Akhremenkov; Anatoly Mixaylovich Tsirlin
This work proposes a structure synthesis and surface distribution algorithm in a heat exchange system for the case when all heat capacity rates and inlet temperatures of the hot streams are constant, while cold streams also have outlet temperatures set. The algorithm includes the possibility of changing the phase state of the contacting streams. The synthesis is based on minimization of dissipation
-
Relativistic Theory of Irreversible Thermodynamics for Multi-Component Fluids and Its Post-Newtonian Limit in Relation to Classical Extended Thermodynamics J. Non Equilib. Thermodyn. (IF 2.157) Pub Date : 2020-04-26 Thoralf Chrobok; Horst-Heino von Borzeszkowski
First, the special-relativistic Theory of Irreversible Processes for a multi-component fluid is formulated. It is based on (i) the balance equations of the particle number and the energy-momentum for the total system (i. e., the mixture of the components) as well as the sub-systems (i. e., the components) and (ii) the dissipation inequality and the Gibbs equation for the mixture. In order to allow
-
Supradegeneracy and the Second Law of Thermodynamics J. Non Equilib. Thermodyn. (IF 2.157) Pub Date : 2020-04-26 Daniel P. Sheehan
Canonical statistical mechanics hinges on two quantities, i. e., state degeneracy and the Boltzmann factor, the latter of which usually dominates thermodynamic behaviors. A recently identified phenomenon (supradegeneracy) reverses this order of dominance and predicts effects for equilibrium that are normally associated with non-equilibrium, including population inversion and steady-state particle and
-
Numerical Examination of Thermophysical Properties of Cobalt Ferroparticles over a Wavy Surface Saturated in Non-Darcian Porous Medium J. Non Equilib. Thermodyn. (IF 2.157) Pub Date : 2020-04-26 Irfan Mustafa; Abuzar Ghaffari; Tariq Javed; Javeria Nawaz Abbasi
In this study, the effect of magnetic field on an incompressible ferrofluid flow along a vertical wavy surface saturated in a porous medium is investigated. Ferrofluid is made by incorporating magnetic particles, in this case cobalt, at the nanoscale level into a base fluid. For the study of porous medium two well-known models, namely, Darcy and non-Darcy, are used. The mathematical model in terms
-
Effects of NP Shapes on Non-Newtonian Bio-Nanofluid Flow in Suction/Blowing Process with Convective Condition: Sisko Model J. Non Equilib. Thermodyn. (IF 2.157) Pub Date : 2020-04-26 Mohamed R. Eid
The present mathematical simulation deals with the study of heat transfer characteristics of the shape of gold nanoparticles (Au-NPs) on blood flow past an exponentially stretching sheet using Sisko nanofluid taking into account the Biot number effect. Influences of non-linear thermal radiation and suction/injection are considered. The one-phase model is used to describe the Sisko nanofluid flow. Similarity
-
Extended Nonequilibrium Variables for 1D Hyperbolic Heat Conduction J. Non Equilib. Thermodyn. (IF 2.157) Pub Date : 2020-03-14 Sergey L. Sobolev; Igor V. Kudinov
We use the Shannon (information) entropy to define an “entropic” temperature for 1D nonequilibrium system with heat flux. In contrast to the kinetic temperature, which is related to the average kinetic energy, the nonequilibrium entropic temperature is related to the changes in entropy and serves as a criterion for thermalization. However, the direction and value of the heat flux is controlled by the
-
Velocity Slip and Entropy Generation Phenomena in Thermal Transport Through Metallic Porous Channel J. Non Equilib. Thermodyn. (IF 2.157) Pub Date : 2020-03-07 Mustafa Turkyilmazoglu
Momentum and thermal transport through open-celled metallic foams filled in a channel of small height is studied in the present technical brief. Fully developed momentum and thermal layers via the Brinkman–Darcy model enable us to obtain closed-form solutions regarding the fluid velocity and temperature distributions of metal and fluid, all depending upon a factor related to the wall slip velocity
-
Investigation on the Use of a Spacetime Formalism for Modeling and Numerical Simulations of Heat Conduction Phenomena J. Non Equilib. Thermodyn. (IF 2.157) Pub Date : 2020-03-05 Roula Al Nahas; Alexandre Charles; Benoît Panicaud; Emmanuelle Rouhaud; Israa Choucair; Kanssoune Saliya; Richard Kerner
The question of frame-indifference of the thermomechanical models has to be addressed to deal correctly with the behavior of matter undergoing finite transformations. In this work, we propose to test a spacetime formalism to investigate the benefits of the covariance principle for application to covariant modeling and numerical simulations for finite transformations. Several models especially for heat