The Experts below are selected from a list of 300 Experts worldwide ranked by ideXlab platform
Xingang Liang - One of the best experts on this subject based on the ideXlab platform.
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heat transfer entropy resistance for the analyses of two stream heat exchangers and two stream heat exchanger networks
Applied Thermal Engineering, 2013Co-Authors: Xuetao Cheng, Xingang LiangAbstract:Abstract The entropy generation minimization method is often used to analyze heat transfer processes from the Thermodynamic viewpoint. In this paper, we analyze common heat transfer processes with the concept of entropy generation, and propose the concept of heat transfer entropy resistance. It is found that smaller heat transfer entropy resistance leads to smaller equivalent Thermodynamic Force difference with prescribed heat transfer rate and larger heat transfer rate with prescribed equivalent Thermodynamic Force difference. With the concept of heat transfer entropy resistance, the performance of two-stream heat exchangers (THEs) and two-stream heat exchanger networks (THENs) is analyzed. For the cases discussed in this paper, it is found that smaller heat transfer entropy resistance always leads to better heat transfer performance for THEs and THENs, while smaller values of the entropy generation, entropy generation numbers and revised entropy generation number do not always.
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analyses of entropy generation and heat entransy loss in heat transfer and heat work conversion
International Journal of Heat and Mass Transfer, 2013Co-Authors: Xuetao Cheng, Xingang LiangAbstract:Abstract Heat entransy loss is defined and both the concepts of entropy generation and heat entransy loss are applied to the analyses of heat-work conversion and heat transfer processes in this paper. In heat-work conversion, it is found that the minimum entropy generation rate relates to the maximum output power under the conditions of the prescribed heat absorption and the equivalent Thermodynamic Forces corresponding to the heat absorption and release of the system, while the maximum heat entransy loss relates to the maximum output power under the conditions of the prescribed heat absorption and the equivalent temperatures corresponding to the heat absorption and release of the system. In heat transfer, the maximum entropy generation rate is consistent with the maximum heat transfer rate with prescribed equivalent Thermodynamic Force difference, while the minimum entropy generation rate corresponds to the minimum equivalent Thermodynamic Force difference with prescribed heat transfer rate. Furthermore, when the concept of heat entransy loss is used, the maximum heat entransy loss rate corresponds to the maximum heat transfer rate with prescribed equivalent temperature difference, while the minimum heat entransy loss rate corresponds to the minimum equivalent temperature difference with prescribed heat transfer rate. The numerical results of some examples verify the theoretical analyses.
Pierre Gaspard - One of the best experts on this subject based on the ideXlab platform.
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Finite-time fluctuation theorem for diffusion-influenced surface reactions
Journal of Statistical Mechanics: Theory and Experiment, 2018Co-Authors: Pierre Gaspard, Raymond KapralAbstract:A finite-time fluctuation theorem is proved for the diffusion-influenced surface reaction A B in a domain with any geometry where the species A and B undergo diffusive transport between the reservoir and the catalytic surface. A corresponding finite-time Thermodynamic Force or affinity is associated with the symmetry of the fluctuation theorem. The time dependence of the affinity and the reaction rates characterizing the stochastic process can be expressed analytically in terms of the solution of deterministic diffusion equations with specific boundary conditions.
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finite time fluctuation theorem for diffusion influenced surface reactions on spherical and janus catalytic particles
arXiv: Statistical Mechanics, 2018Co-Authors: Pierre Gaspard, Patrick Grosfils, Mu Jie Huang, Raymond KapralAbstract:A finite-time fluctuation theorem for the diffusion-influenced surface reaction A B is investigated for spherical and Janus catalytic particles. The finite-time rates and Thermodynamic Force are analytically calculated by solving diffusion equations with the special boundary conditions of the finite-time fluctuation theorem. Theory is compared with numerical simulations carried out with two different methods: a random walk algorithm and multiparticle collision dynamics.
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fluctuation theorems and the nonequilibrium Thermodynamics of molecular motors
Physical Review E, 2006Co-Authors: David Andrieux, Pierre GaspardAbstract:The fluctuation theorems for the currents and the dissipated work are considered for molecular motors which are driven out of equilibrium by chemical reactions. Because of the molecular fluctuations, these nonequilibrium processes are described by stochastic models based on a master equation. Analytical expressions are derived for the fluctuation theorems, allowing us to obtain predictions on the work dissipated in the motor as well as on its rotation near and far from Thermodynamic equilibrium. We show that the fluctuation theorems provide a method to determine the affinity or Thermodynamic Force driving the motor. This affinity is given in terms of the free enthalpy of the chemical reactions. The theorems are applied to the F1 rotary motor which turns out to be a stiff system typically functioning in the nonlinear regime of nonequilibrium Thermodynamics. We show that this nonlinearity confers a robustness to the functioning of the molecular motor.
Katja Lindenberg - One of the best experts on this subject based on the ideXlab platform.
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Three-stage stochastic pump: Another type of Onsager-Casimir symmetry and results far from equilibrium
Physical Review E, 2018Co-Authors: Alexandre Rosas, Christian Van Den Broeck, Katja LindenbergAbstract:The stochastic Thermodynamic analysis of a time-periodic single particle pump sequentially exposed to three thermochemical reservoirs is presented. The analysis provides explicit results for flux, Thermodynamic Force, entropy production, work, and heat. These results apply near equilibrium as well as far from equilibrium. In the linear response regime, a different type of Onsager-Casimir symmetry is uncovered. The Onsager matrix becomes symmetric in the limit of zero dissipation.
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Stochastic Thermodynamics for a periodically driven single-particle pump.
Physical Review E, 2017Co-Authors: Alexandre Rosas, Christian Van Den Broeck, Katja LindenbergAbstract:We present the stochastic Thermodynamic analysis of a time-periodic single-particle pump, including explicit results for flux, Thermodynamic Force, entropy production, work, heat, and efficiency. These results are valid far from equilibrium. The deviations from the linear (Onsager) regime are discussed.
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Extracting chemical energy by growing disorder: efficiency at maximum power
Journal of Statistical Mechanics: Theory and Experiment, 2010Co-Authors: Massimiliano Esposito, Katja Lindenberg, Christian Van Den BroeckAbstract:We consider the efficiency of chemical energy extraction from the environment by the growth of a copolymer made of two constituent units in the entropy-driven regime. We show that the Thermodynamic nonlinearity associated with the information processing aspect is responsible for a branching of the system properties such as power, speed of growth, entropy production, and efficiency, with varying affinity. The standard linear Thermodynamics argument which predicts an efficiency of 1/2 at maximum power is inappropriate because the regime of maximum power is located either outside of the linear regime or on a separate bifurcated branch, and because the usual Thermodynamic Force is not the natural variable for this optimization.
Xuetao Cheng - One of the best experts on this subject based on the ideXlab platform.
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heat transfer entropy resistance for the analyses of two stream heat exchangers and two stream heat exchanger networks
Applied Thermal Engineering, 2013Co-Authors: Xuetao Cheng, Xingang LiangAbstract:Abstract The entropy generation minimization method is often used to analyze heat transfer processes from the Thermodynamic viewpoint. In this paper, we analyze common heat transfer processes with the concept of entropy generation, and propose the concept of heat transfer entropy resistance. It is found that smaller heat transfer entropy resistance leads to smaller equivalent Thermodynamic Force difference with prescribed heat transfer rate and larger heat transfer rate with prescribed equivalent Thermodynamic Force difference. With the concept of heat transfer entropy resistance, the performance of two-stream heat exchangers (THEs) and two-stream heat exchanger networks (THENs) is analyzed. For the cases discussed in this paper, it is found that smaller heat transfer entropy resistance always leads to better heat transfer performance for THEs and THENs, while smaller values of the entropy generation, entropy generation numbers and revised entropy generation number do not always.
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analyses of entropy generation and heat entransy loss in heat transfer and heat work conversion
International Journal of Heat and Mass Transfer, 2013Co-Authors: Xuetao Cheng, Xingang LiangAbstract:Abstract Heat entransy loss is defined and both the concepts of entropy generation and heat entransy loss are applied to the analyses of heat-work conversion and heat transfer processes in this paper. In heat-work conversion, it is found that the minimum entropy generation rate relates to the maximum output power under the conditions of the prescribed heat absorption and the equivalent Thermodynamic Forces corresponding to the heat absorption and release of the system, while the maximum heat entransy loss relates to the maximum output power under the conditions of the prescribed heat absorption and the equivalent temperatures corresponding to the heat absorption and release of the system. In heat transfer, the maximum entropy generation rate is consistent with the maximum heat transfer rate with prescribed equivalent Thermodynamic Force difference, while the minimum entropy generation rate corresponds to the minimum equivalent Thermodynamic Force difference with prescribed heat transfer rate. Furthermore, when the concept of heat entransy loss is used, the maximum heat entransy loss rate corresponds to the maximum heat transfer rate with prescribed equivalent temperature difference, while the minimum heat entransy loss rate corresponds to the minimum equivalent temperature difference with prescribed heat transfer rate. The numerical results of some examples verify the theoretical analyses.
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Entropy resistance minimization: An alternative method for heat exchanger analyses
Energy, 2013Co-Authors: Xuetao ChengAbstract:Abstract In this paper, the concept of entropy resistance is proposed based on the entropy generation analyses of heat transfer processes. It is shown that smaller entropy resistance leads to larger heat transfer rate with fixed Thermodynamic Force difference and smaller Thermodynamic Force difference with fixed heat transfer rate, respectively. For the discussed two-stream heat exchangers in which the heat transfer rates are not given and the three-stream heat exchanger with prescribed heat capacity flow rates and inlet temperatures of the streams, smaller entropy resistance leads to larger heat transfer rate. For the two-stream heat exchangers with fixed heat transfer rate, smaller entropy resistance leads to larger effectiveness. Furthermore, it is shown that smaller values of the concepts of entropy generation numbers and modified entropy generation number do not always correspond to better performance of the discussed heat exchangers.
F D Fischer - One of the best experts on this subject based on the ideXlab platform.
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deformation stress state and Thermodynamic Force for a growing void in an elastic plastic material
International Journal of Plasticity, 2009Co-Authors: F D Fischer, Thomas AntretterAbstract:Abstract The growth of a spherical void in an elastic–plastic body, subjected to external pressure or tension and a gas pressure as well as a surface stress at the void surface, is investigated. The deformation, strain and stress state in the full body is presented. In addition, the local and global energy terms are calculated. Finally the total Thermodynamic Force on the void surface as well as the total dissipation are evaluated and compared allowing the calculation of the mechanical contribution to void growth due to diffusion of vacancies generated by plastification or irradiation.
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deformation stress state and Thermodynamic Force for a transforming spherical inclusion in an elastic plastic material
Journal of Applied Mechanics, 2000Co-Authors: F D Fischer, E R OberaignerAbstract:The progress of a transformed phase into an elastic-plastic parent phase is simulated by a growing sphere. The transformation is accompanied by a dilatational volume change. The strain and stress state in the full space is presented. In addition, the local and global energy terms are calculated. Finally the Thermodynamic Forces on the interface are derived. Also strain hardening is considered.
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a criterion for the martensitic transformation of a microregion in an elastic plastic material
Acta Materialia, 1998Co-Authors: F D Fischer, G ReisnerAbstract:Abstract A derivation of a Thermodynamic transformation criterion for the martensitic transformation from a f.c.c. to a b.c.t. lattice is presented in a continuum mechanical framework. The Thermodynamic Force at a point of an interface is determined and discussed in the light of earlier literature. Starting from this local Thermodynamic Force a global rate of energy balance is given. The integration of this relation over the time interval within which a certain microregion transforms yields the transformation criterion. Driving and dragging Forces are discussed in detail.
