### Abstract

Language | English |
---|---|

Pages | 6079-6094 |

Number of pages | 16 |

Journal | Physica A: Statistical Mechanics and its Applications |

Volume | 387 |

Issue number | 24 |

DOIs | |

Publication status | Published - 15 Oct 2008 |

### Fingerprint

### Keywords

- gas kinetic theory
- Boltzmann equation
- compressible fluids
- Navier-Stokes equations
- rarefied gas dynamics
- constitutive relations

### Cite this

*Physica A: Statistical Mechanics and its Applications*,

*387*(24), 6079-6094. https://doi.org/10.1016/j.physa.2008.07.009

}

*Physica A: Statistical Mechanics and its Applications*, vol. 387, no. 24, pp. 6079-6094. https://doi.org/10.1016/j.physa.2008.07.009

**A continuum model of gas flows with localized density variations.** / Dadzie, S.K.; Reese, J.M.; McInnes, C.R.

Research output: Contribution to journal › Article

TY - JOUR

T1 - A continuum model of gas flows with localized density variations

AU - Dadzie, S.K.

AU - Reese, J.M.

AU - McInnes, C.R.

PY - 2008/10/15

Y1 - 2008/10/15

N2 - We discuss the kinetic representation of gases and the derivation of macroscopic equations governing the thermomechanical behavior of a dilute gas viewed at the macroscopic level as a continuous medium. We introduce an approach to kinetic theory where spatial distributions of the molecules are incorporated through a mean-free-volume argument. The new kinetic equation derived contains an extra term involving the evolution of this volume, which we attribute to changes in the thermodynamic properties of the medium. Our kinetic equation leads to a macroscopic set of continuum equations in which the gradients of thermodynamic properties, in particular density gradients, impact on diffusive fluxes. New transport terms bearing both convective and diffusive natures arise and are interpreted as purely macroscopic expansion or compression. Our new model is useful for describing gas flows that display non-local-thermodynamic-equilibrium (rarefied gas flows), flows with relatively large variations of macroscopic properties, and/or highly compressible fluid flows.

AB - We discuss the kinetic representation of gases and the derivation of macroscopic equations governing the thermomechanical behavior of a dilute gas viewed at the macroscopic level as a continuous medium. We introduce an approach to kinetic theory where spatial distributions of the molecules are incorporated through a mean-free-volume argument. The new kinetic equation derived contains an extra term involving the evolution of this volume, which we attribute to changes in the thermodynamic properties of the medium. Our kinetic equation leads to a macroscopic set of continuum equations in which the gradients of thermodynamic properties, in particular density gradients, impact on diffusive fluxes. New transport terms bearing both convective and diffusive natures arise and are interpreted as purely macroscopic expansion or compression. Our new model is useful for describing gas flows that display non-local-thermodynamic-equilibrium (rarefied gas flows), flows with relatively large variations of macroscopic properties, and/or highly compressible fluid flows.

KW - gas kinetic theory

KW - Boltzmann equation

KW - compressible fluids

KW - Navier-Stokes equations

KW - rarefied gas dynamics

KW - constitutive relations

U2 - 10.1016/j.physa.2008.07.009

DO - 10.1016/j.physa.2008.07.009

M3 - Article

VL - 387

SP - 6079

EP - 6094

JO - Physica A: Statistical Mechanics and its Applications

T2 - Physica A: Statistical Mechanics and its Applications

JF - Physica A: Statistical Mechanics and its Applications

SN - 0378-4371

IS - 24

ER -