Breakdown parameter for kinetic modeling of multiscale gas flows

Jianping Meng, Nishanth Dongari, Jason M. Reese, Yonghao Zhang*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


Multiscale methods built purely on the kinetic theory of gases provide information about the molecular velocity distribution function. It is therefore both important and feasible to establish new breakdown parameters for assessing the appropriateness of a fluid description at the continuum level by utilizing kinetic information rather than macroscopic flow quantities alone. We propose a new kinetic criterion to indirectly assess the errors introduced by a continuum-level description of the gas flow. The analysis, which includes numerical demonstrations, focuses on the validity of the Navier-Stokes-Fourier equations and corresponding kinetic models and reveals that the new criterion can consistently indicate the validity of continuum-level modeling in both low-speed and high-speed flows at different Knudsen numbers.

Original languageEnglish
Article number063305
Number of pages9
JournalPhysical Review E - Statistical, Nonlinear and Soft Matter Physics
Issue number6
Publication statusPublished - 13 Jun 2014


  • molecular dynamics
  • arbitrary geometries
  • rarefied gas dynamics
  • breakdown parameter
  • multiscale simulation
  • Boltzmann equation
  • transition-continuum regime
  • kinetic theory
  • gas flows
  • Knudsen number
  • lattice Boltzmann

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