Behaviour of microscale gas flows based on a power-law free path distribution function

Nishanth Dongari, Yonghao Zhang, Jason Reese

Research output: Chapter in Book/Report/Conference proceedingChapter

5 Citations (Scopus)
78 Downloads (Pure)


We investigate a power-law form for the probability distribution function of free paths of dilute gas molecules in a confined region. A geometry-dependent effective molecular mean free path (MFP) model is then derived for a planar wall
confinement, by taking into account the boundary limiting effects on the molecular paths. The power-law based effective MFP is validated against molecular dynamics simulation data and compared with exponential effective MFP models. The Navier-Stokes constitutive relations are then modified according to the kinetic theory of gases i.e. transport properties can be described in terms of the free paths which the molecules describe between collisions. Results for isothermal pressure-driven Poiseuille gas flows in micro-channels are reported, and we compare results with conventional hydrodynamic models, solutions of the Boltzmann equation and experimental data.
Original languageEnglish
Title of host publicationRarefied Gas Dynamics
EditorsD.A Levin, I.J Wysong, A.L Garcia, H Abarbanel
Number of pages6
ISBN (Print)978-0-7354-0889-0
Publication statusPublished - 28 Jun 2011
Event27th International Symposium on Rarefied Gas Dynamics - Pacific Grove, Claifornia, United States
Duration: 10 Jul 201015 Jul 2010

Publication series

NameAIP Conference Proceedings
ISSN (Print)0094-243X


Conference27th International Symposium on Rarefied Gas Dynamics
Country/TerritoryUnited States
CityPacific Grove, Claifornia,


  • microscale gas flows
  • Knudsen layer
  • molecular mean free path
  • slip flows


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