Nonequilibrium kinetic temperatures in flowing gases

Criado-Sancho, M.; Jou, David; Casas-Vázquez, José

doi:10.1016/j.physleta.2005.10.043

Cited by 35 publications

(29 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This is in accordance with the experimental evidence that the local-equilibrium temperature loses its validity in situations where the deviation from equilibrium ensemble is not negligible, as for example the heat propagation in nanosystems [22,30,36,[39][40][41].…”

Section: Second-order Nonlocal Effectssupporting

confidence: 90%

Constitutive equations for heat conduction in nanosystems and nonequilibrium processes: an overview

Jou¹,

Cimmelli

2016

Communications in Applied and Industrial Mathematics

View full text Add to dashboard Cite

show abstract

Section: Second-order Nonlocal Effectssupporting

confidence: 90%

Constitutive equations for heat conduction in nanosystems and nonequilibrium processes: an overview

Jou¹,

Cimmelli

2016

Communications in Applied and Industrial Mathematics

View full text Add to dashboard Cite

show abstract

“…The behavior of the x, y, and z components of both the kinetic and configurational temperatures for a strongly nonequilibrium system has been studied by Baranyai [7], who concluded that the introduction of a synthetic homogeneous thermostat induces greater temperature anisotropy than is present in a system that is naturally thermostatted by a spatial heat flux. The divergence of the directional kinetic temperatures for an ideal gas in strong shear flow has also been calculated using kinetic theory by Criado-Sancho, Jou, and Casas-Vázquez [8]. Hoover [9] has investigated this problem by directly comparing the results of homogeneous shear simulations with those of inhomogeneous, boundary driven shear.…”

Section: Introductionmentioning

confidence: 99%

Effect of kinetic and configurational thermostats on calculations of the first normal stress coefficient in nonequilibrium molecular dynamics simulations

2012

View full text Add to dashboard Cite

Thermostats for homogeneous nonequilibrium molecular dynamics simulations are usually designed to control the kinetic temperature, but it is now possible control any combination of many different types of temperature, including the configurational and kinetic temperatures and their directional components. It is well known that these temperatures can become unequal in homogeneously thermostatted shearing steady states. The microscopic expressions for these temperatures are all derived from equilibrium distribution functions, and it is pertinent to ask, what are the consequences of using these equilibrium microscopic expressions for temperature in thermostats for shearing nonequilibrium steady states? Here we show that the answer to this question depends on which properties are being investigated. We present numerical results showing that the value of the zero shear rate viscosity obtained by extrapolating results of nonequilibrium molecular dynamics simulations of shearing steady states is the same, regardless of the type of temperature that is controlled. It also agrees with the value obtained from the equilibrium stress autocorrelation function via the Green-Kubo relation. However, the values of the limiting zero shear rate first normal stress coefficient obtained from nonequilibrium molecular dynamics simulations of shearing steady states are strongly dependent on the choice of temperature being controlled. They also differ from the value of the first normal stress coefficient that is calculated from the equilibrium stress autocorrelation function. We show that even when all of the directional components of the kinetic and configurational temperatures are simultaneously controlled to the same value, the agreement with the result obtained from the equilibrium stress autocorrelation function is poor.

show abstract

“…There are different definitions of temperature: thermometric, caloric, entropic, kinetic, vibrational, configurational, fluctuational, and so on (see [1], [2], [3], [4], [5], [6], [7] and [8] ). In this section we introduce the definitions of caloric, entropic and thermometric temperature and we compare them in equilibrium thermodynamics and in non-equilibrium thermodynamics in steady states.…”

Section: Equilibrium Temperatures Versus Non-equilibrium Temperaturesmentioning

confidence: 99%

“…In Section 2 of this paper we introduce the equilibrium temperature versus non-equilibrium temperatures (see [1], [2], [3], [4], [5], [6], [7] and [8] for applications on this subject).…”

Section: Introductionmentioning

confidence: 99%

Non-equilibrium temperatures and heat transport in nanosystems with defects, described by a tensorial internal variable

Restuccia

2016

Communications in Applied and Industrial Mathematics

View full text Add to dashboard Cite

The paper deals with the meaning of non-equilibrium temperatures in nanosystems with an internal variable, describing defects inside them, and implications on heat transport. In equilibrium all definitions of temperature lead to the same value, but in nonequilibrium steady states they lead to different values, giving information on different degrees of freedom. We discuss the caloric and entropic non-equilibrium temperatures and the relations among them, in defective nanosystems (crystals with dislocations or porous channels, carbon nanotubes in a solid matrix and so on), crossed by an external energy flux. Here, we present a model for nanocrystals with dislocation defects submitted to an external energy flux. The dislocations may have a strong influence on the effective thermal conductivity, and their own dynamics may be coupled in relevant way to the heat flux dynamics. In the linear case the constitutive relations, the rate equations for the internal variable and the heat flux are worked out and a generalized telegraphic heat equation is derived in the anisotropic and isotropic case, describing the thermal disturbances with finite velocity.

show abstract

Nonequilibrium kinetic temperatures in flowing gases

Cited by 35 publications

References 22 publications

Constitutive equations for heat conduction in nanosystems and nonequilibrium processes: an overview

Constitutive equations for heat conduction in nanosystems and nonequilibrium processes: an overview

Effect of kinetic and configurational thermostats on calculations of the first normal stress coefficient in nonequilibrium molecular dynamics simulations

Non-equilibrium temperatures and heat transport in nanosystems with defects, described by a tensorial internal variable

Contact Info

Product

Resources

About