Definition of the Perfect Gas and Its Relation to the Second Law of Thermodynamics

1960 ◽  
Vol 28 (9) ◽  
pp. 796-798 ◽  
Author(s):  
Donald G. Miller ◽  
Warren Dennis
Keyword(s):  
Second Law Of Thermodynamics ◽  
Second Law ◽  
Perfect Gas ◽  
Definition Of

scholarly journals Diffusive Bejan number and second law of thermodynamics toward a new dimensionless formulation of fluid dynamics laws

2019 ◽  
Vol 23 (6 Part B) ◽  
pp. 4005-4022 ◽  
Author(s):  
Michele Trancossi ◽  
Jose Pascoa
Keyword(s):  
Fluid Dynamics ◽  
Entropy Generation ◽  
Fluid Dynamic ◽  
Second Law Of Thermodynamics ◽  
Integral Form ◽  
Second Law ◽  
Bejan Number ◽  
Definition Of ◽  
New Formulation ◽  
Dimensionless Formulation

In a recent paper, Liversage and Trancossi have defined a new formulation of drag as a function of the dimensionless Bejan and Reynolds numbers. Further analysis of this hypothesis has permitted to obtain a new dimensionless formulation of the fundamental equations of fluid dynamics in their integral form. The resulting equations have been deeply discussed for the thermodynamic definition of Bejan number evidencing that the proposed formulation allows solving fluid dynamic problems in terms of entropy generation, allowing an effective optimization of design in terms of the Second law of thermodynamics. Some samples are discussed evidencing how the new formulation can support the generation of an optimized configuration of fluidic devices and that the optimized configurations allow minimizing the entropy generation.

Thermodynamic Modeling for Discrete-Time Large-Scale Dynamical Systems

2011 ◽  
Author(s):  
Wassim M. Haddad ◽  
Sergey G. Nersesov
Keyword(s):  
Dynamical System ◽  
Dynamical Systems ◽  
Thermodynamic Modeling ◽  
Discrete Time ◽  
Large Scale ◽  
Type Inequality ◽  
Second Law Of Thermodynamics ◽  
Second Law ◽  
Thermodynamic Models ◽  
Definition Of

This chapter describes the thermodynamic modeling of discrete-time large-scale dynamical systems. In particular, it develops nonlinear discrete-time compartmental models that are consistent with thermodynamic principles. Since thermodynamic models are concerned with energy flow among subsystems, the chapter constructs a nonlinear compartmental dynamical system model characterized by conservation of energy and the first law of thermodynamics. It then provides a deterministic definition of entropy for a large-scale dynamical system that is consistent with the classical thermodynamic definition of entropy and shows that it satisfies a Clausius-type inequality leading to the law of entropy nonconservation. The chapter also considers nonconservation of entropy and the second law of thermodynamics, nonconservation of ectropy, semistability of discrete-time thermodynamic models, entropy increase and the second law of thermodynamics, and thermodynamic models with linear energy exchange.

Entropy Increase as Tendency: Drive and Effector

2017 ◽  
pp. 93-96
Author(s):  
Alberto Gianinetti
Keyword(s):  
Particle Motion ◽  
Second Law Of Thermodynamics ◽  
Second Law ◽  
Entropy Increase ◽  
Probable State ◽  
Definition Of

A useful definition of entropy is “a function of the system equilibration, stability, and inertness”, and the tendency to an overall increase of entropy, which is set forth by the second law of thermodynamics, should be meant as “the tendency to the most probable state”, that is, to a state having the highest equilibration, stability, and inertness that the system can reach. The tendency to entropy increase is driven by the probabilistic distributions of matter and energy and it is actualized by particle motion.

SEN Analysis of Stratified Hot Water Heat Stores With Respect to Axial Position and Number of Charging-Discharging Equipments

2008 ◽  
Author(s):  
Varghese Panthalookaran
Keyword(s):  
Entropy Generation ◽  
Fluid Dynamic ◽  
Second Law Of Thermodynamics ◽  
Efficiency Index ◽  
Hot Water ◽  
Dead Volume ◽  
Axial Position ◽  
Working Fluid ◽  
Second Law ◽  
Definition Of

SEN analysis [Solar Energy, 2007, Vol. 81, pp. 1043–1054] is a robust characterization method for stratified thermal energy stores (TES). It integrates the concerns of the First and Second Law of Thermodynamics into single efficiency index. The First Law concern is incorporated into the definition of SEN efficiency index through energy response factor (ER) and the Second Law concern through entropy generation ratio (REG). SEN analysis thus estimates the ability of a TES to store energy and exergy. In the current paper SEN analysis is utilized to characterize hot water heat stores (HWHS) with respect to the axial position and number of charging/discharging equipments they possess. Diffusers or flow-guides are used as charging-discharging equipments in view of reducing turbulent mixing within the HWHS, especially in the entrance and exit ports. For HWHS charging-discharging equipments are commonly positioned in the top-most and bottom-most regions of the HWHS in order to avoid development of dead volume, i.e., volume that does not take part in the charging-discharging process. Axially placed conical diffusers are observed to circumvent the issue of dead volumes. However, the effect of their axial position on the entropy generation is not yet studied. Further, one may use intermediate charging-discharging equipment in association with the original pair in order to feed or withdraw the working fluid into/from the HWHS at different heights. This paper provides a detailed analysis of the position and number of axially placed conical diffusers with zero diffuser angles inside a cylindrical HWHS. The thermal field information obtained from a computational fluid dynamic (CFD) analysis is subjected to the SEN analysis to achieve required design insights.

scholarly journals The second law of thermodynamics as variation on a theme of Carathéodory

2021 ◽  
Vol 477 (2253) ◽  
pp. 20210425
Author(s):  
Joe D. Goddard
Keyword(s):  
Energy Balance ◽  
State Space ◽  
Internal Energy ◽  
Second Law Of Thermodynamics ◽  
Irreversible Processes ◽  
Second Law ◽  
Classic Work ◽  
Axiomatic Foundation ◽  
Convexity Properties ◽  
Definition Of

This paper revisits the second law of thermodynamics via certain modifications of the axiomatic foundation provided by the celebrated 1909 work of Carathéodory. It is shown that his postulate of adiabatic inaccessibility represents one of several constraints on the energy balance that serve to establish the existence of thermostatic entropy as a foliation of state space, with temperature representing a force of constraint. To achieve the thermostatic version of the second law, as embodied in the postulates of Clausius and Gibbs, work principles are proposed to define thermostatic equilibrium and stability in terms of the convexity properties of internal energy, entropy and related thermostatic potentials. Comparisons are made with the classic work of Coleman and Noll on thermostatic equilibrium in simple continua, resulting in a few unresolved differences. Perhaps the most novel aspect of the current work is an extension to irreversible processes by means of a non-equilibrium entropy derived from recoverable work, which generalizes similar ideas in continuum viscoelasticity. This definition of entropy calls for certain revisions of modern theories of continuum thermomechanics by Coleman, Noll and others that are based on a generally inaccessible entropy and undefined temperature.

scholarly journals The second laws of quantum thermodynamics

2015 ◽  
Vol 112 (11) ◽  
pp. 3275-3279 ◽  
Author(s):  
Fernando Brandão ◽  
Michał Horodecki ◽  
Nelly Ng ◽  
Jonathan Oppenheim ◽  
Stephanie Wehner
Keyword(s):  
Heat Bath ◽  
Second Law Of Thermodynamics ◽  
State Transitions ◽  
Second Law ◽  
Free Energies ◽  
Entire Family ◽  
Long Range Interactions ◽  
Laws Of Thermodynamics ◽  
Apparent Violation ◽  
Definition Of

The second law of thermodynamics places constraints on state transformations. It applies to systems composed of many particles, however, we are seeing that one can formulate laws of thermodynamics when only a small number of particles are interacting with a heat bath. Is there a second law of thermodynamics in this regime? Here, we find that for processes which are approximately cyclic, the second law for microscopic systems takes on a different form compared to the macroscopic scale, imposing not just one constraint on state transformations, but an entire family of constraints. We find a family of free energies which generalize the traditional one, and show that they can never increase. The ordinary second law relates to one of these, with the remainder imposing additional constraints on thermodynamic transitions. We find three regimes which determine which family of second laws govern state transitions, depending on how cyclic the process is. In one regime one can cause an apparent violation of the usual second law, through a process of embezzling work from a large system which remains arbitrarily close to its original state. These second laws are relevant for small systems, and also apply to individual macroscopic systems interacting via long-range interactions. By making precise the definition of thermal operations, the laws of thermodynamics are unified in this framework, with the first law defining the class of operations, the zeroth law emerging as an equivalence relation between thermal states, and the remaining laws being monotonicity of our generalized free energies.

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