Modeling of Knudsen layer effects in micro/nanoscale gas flows

Nishanth Dongari, Yonghao Zhang, Jason Reese

Research output: Contribution to journalArticle

57 Citations (Scopus)
356 Downloads (Pure)

Abstract

We propose a power-law based effective mean free path (MFP) model so that the Navier-Stokes-Fourier equations can be employed for the transition-regime flows typical of gas micro/nanodevices. The effective MFP model is derived for a system with planar wall confinement by taking into account the boundary limiting effects on the molecular free paths. Our model is validated against molecular dynamics simulation data and compared with other theoretical models. As gas transport properties can be related to the mean free path through kinetic theory, the Navier-Stokes-Fourier constitutive relations are then modified in order to better capture the flow behavior in the Knudsen layers close to surfaces. Our model is applied to fully developed isothermal pressure-driven (Poiseuille) and thermal creep gas flows in microchannels. The results show that our approach greatly improves the near-wall accuracy of the Navier-Stokes-Fourier equations, well beyond the slip-flow regime.
Original languageEnglish
Article number071101
Number of pages10
JournalJournal of Fluids Engineering
Volume133
Issue number7
DOIs
Publication statusPublished - Jul 2011

Keywords

  • creeping flow
  • kinetic theory
  • Knudsen flow
  • microchannel flor
  • Poiseuille flow
  • navier stokes equations

Fingerprint Dive into the research topics of 'Modeling of Knudsen layer effects in micro/nanoscale gas flows'. Together they form a unique fingerprint.

  • Equipment

  • Cite this