Extension of the DSMC method to high pressure flows

Evgeny V. Titov, Deborah A. Levin

Research output: Contribution to journalArticle

Abstract

A collision-limiter method, designated as equilibrium direct simulation Monte Carlo (eDSMC), is proposed to extend the DSMC technique to high pressure flows. The method is similar to collision-limiter schemes considered in the past with the important distinction that for inviscid flows, equilibrium is enforced in the entire flow by providing a sufficient number of collisions, based on pre-simulation testing. To test the method with standard DSMC and Navier-Stokes (NS) methods, axi-symmetric nozzle and embedded-channel flows are simulated and compared with experimental temperature data and pre-existing calculations, respectively. The method is shown to agree with third-order Eulerian nozzle flows and first-order channel flows. Chapman-Enskog theory is utilized to predict the range of initial conditions where eDSMC is potentially useful for modeling flows that contain viscous boundary layer regions. Comparison with supersonic nozzle data suggests that the eDSMC method is not adequate for capturing the large variation in flow length scales occurring in supersonic expansions into a vacuum. However, when eDSMC is used in combination with the baseline-DSMC method a near-exact solution is obtained with a considerable computational savings compared to the exact DSMC solution. Viscous flow channel calculations are found to agree well with an exact Navier-Stokes (NS) calculation for a small Knudsen number case as predicted by Chapman-Enskog theory.

Original languageEnglish (US)
Pages (from-to)351-368
Number of pages18
JournalInternational Journal of Computational Fluid Dynamics
Volume21
Issue number9-10
DOIs
StatePublished - Oct 1 2007
Externally publishedYes

Keywords

  • Collision limiter
  • DSMC
  • Nozzle flow

ASJC Scopus subject areas

  • Computational Mechanics
  • Aerospace Engineering
  • Condensed Matter Physics
  • Energy Engineering and Power Technology
  • Mechanics of Materials
  • Mechanical Engineering

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