Thermal rarefied gas flow investigations through micro/nano backward-facing step: Comparison of DSMC and CFD subject to hybrid slip and jump boundary conditions

Amir-Mehran Mahdavi, Nam TP Le, Ehsan Roohi, Craig White

Research output: Contribution to journalArticle

11 Citations (Scopus)

Abstract

This paper evaluates the suitability of a newly developed hybrid “Langmuir-Maxwell” and “Langmuir-Smoluchowski” slip/jump boundary conditions in the Navier-Stokes-Fourier equations for nano/micro backward-facing step geometry flow which experiences separation and reattachment. Additionally, this
paper investigates the effect of different parameters such as step pressure ratio, inflow temperature and wall temperature on the separation zone in the nano/micro step geometry. We chose nitrogen as the working gas and use two DSMC solvers to assess the accuracy of the CFD solutions. DSMC results
showed that the increase of the inlet temperatures extends the length of the separation zone and raises the mass flow rate. The change of pressure ratio does not affect the separation length while the increase of the step wall temperature decreases the length of this zone for both CFD and DSMC results. Compared to the DSMC results, the hybrid slip/jump boundary conditions predict better surface pressure, surface gas temperature and slip velocity in the separation zone than the standard Maxwell/Smoluchowski boundary
conditions.
LanguageEnglish
Pages733-755
Number of pages37
JournalNumerical Heat Transfer Part A: Applications
Volume66
Issue number7
Early online date25 Jun 2014
DOIs
Publication statusPublished - 1 Oct 2014

Fingerprint

Rarefied Gas Flow
Backward-facing Step
backward facing steps
Direct Simulation Monte Carlo
rarefied gases
charge flow devices
Slip
gas flow
Flow of gases
Computational fluid dynamics
Jump
slip
Boundary conditions
boundary conditions
pressure ratio
wall temperature
Temperature
flow geometry
inlet temperature
Geometry

Keywords

  • rarefied gas flows
  • slip velocity
  • DSMC
  • CFD method
  • hybrid approach
  • boundary analysis

Cite this

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Thermal rarefied gas flow investigations through micro/nano backward-facing step : Comparison of DSMC and CFD subject to hybrid slip and jump boundary conditions. / Mahdavi, Amir-Mehran; Le, Nam TP; Roohi, Ehsan; White, Craig.

In: Numerical Heat Transfer Part A: Applications, Vol. 66, No. 7, 01.10.2014, p. 733-755.

Research output: Contribution to journalArticle

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