An approximate method for solving rarefied and transitional flows using TDEFM with isotropic mesh adaptation

Smith, M. R., Cave, H. M., Wu, J. S. and Macrossan, M. N. (2009). An approximate method for solving rarefied and transitional flows using TDEFM with isotropic mesh adaptation. In: Takashi Abe, AIP Conference Proceedings. Rarefied gas dynamics : Proceedings of the 26th International Symposium on Rarefied Gas Dynamics : RGD26. 26th International Symposium on Rarefied Gas Dynamics, Kyoto, Japan, (371-376). 20-25 July 2008.

Attached Files (Some files may be inaccessible until you login with your UQ eSpace credentials)
Name Description MIMEType Size Downloads
RGD26_Smithetal.pdf Author pre-print application/pdf 116.19KB 91

Author Smith, M. R.
Cave, H. M.
Wu, J. S.
Macrossan, M. N.
Title of paper An approximate method for solving rarefied and transitional flows using TDEFM with isotropic mesh adaptation
Conference Paper Type Fully Published Paper
Conference name 26th International Symposium on Rarefied Gas Dynamics
DOI 10.1063/1.3076504
Conference location Kyoto, Japan
Conference dates 20-25 July 2008
Proceedings title AIP Conference Proceedings. Rarefied gas dynamics : Proceedings of the 26th International Symposium on Rarefied Gas Dynamics : RGD26
Journal name Rarefied Gas Dynamics
Editor Takashi Abe
Place published New York , U.S.A.
Publisher American Institute of Physics
Publication date 2009
Year available 2009
Volume number 1084
Issue number 1
ISBN 9780735406155; 0735406154
ISSN 0094-243X; 1551-7616; 1935-0465
Start page 371
End page 376
Total pages 6
Collection year 2010
Language eng
Abstract/Summary DSMC [1] can become increasingly expensive when extended to the near-continuum regime. Because of the statistical nature of the results, long run times are required to build up samples of simulator particles large enough to reduce the statistical scatter to acceptable levels. Here we adapt a kinetic theory based flux method to produce a quick approximate solver for transition and near-continuum flows. The results have no statistical scatter. The CPU times are similar to those of traditional continuum (Navier-Stokes or Euler) solvers. The True Direction Equilibrium Flux Method (TDEFM) [2, 3] is a generalisation of Pullin's kinetic theory based EFM [4]. TDEFM can transfer fluxes of mass, momentum and energy in physically realistic directions from any source cell to any destination cell, even if the cells do not share an interface. TDEFM, as an Euler solver, has been shown to provide good results on a Cartesian grid for flows where standard continuum methods produce unphysical asymmetries apparently because the continuum fluxes are constrained (in one time step) to flow in the grid coordinate directions rather than the correct physical direction. [2, 3] The new method for rarefied flow does not try to produce the correct velocity distribution function, but does ensure that mass, momentum and energy are transported within the flow over the physically correct distances between “pseudo-collisions.” To ensure this, (1) the time step is restricted so that mass, momentum and energy are exchanged between contiguous cells only in one time step, and (2) the cells sizes are adapted, as steady state is approached, to be approximately equal to the local mean free path. The results for Mach 5 flow over a flat plate for varying Knudsen numbers show an average difference (compared to DSMC) in the X-velocity profile near the surface of the plate of less than 6 percent. TDEFM, employing adaptive mesh refinement, required less than 9 percent of the computational time required by DSMC for the same flow. Thus the approximate method could be useful for quick “first-estimate” solutions of otherwise time consuming design problems. ©2009 American Institute of Physics
Subjects E1
970109 Expanding Knowledge in Engineering
880305 Space Transport
091399 Mechanical Engineering not elsewhere classified
Keyword Kinetic theory of gases
CFD
DSMC
EPSM
EFM
TDEFM
Direct simulation
Euler equations
Rarefied gas dynamics
Q-Index Code E1
Q-Index Status Confirmed Code
Additional Notes Series title: AIP conference proceedings, no. 1084.

Document type: Conference Paper
Sub-type: Fully Published Paper
Collections: 2010 Higher Education Research Data Collection
School of Mechanical & Mining Engineering Publications
 
Versions
Version Filter Type
Citation counts: TR Web of Science Citation Count  Cited 0 times in Thomson Reuters Web of Science Article
Scopus Citation Count Cited 0 times in Scopus Article
Google Scholar Search Google Scholar
Access Statistics: 82 Abstract Views, 91 File Downloads  -  Detailed Statistics
Created: Thu, 25 Mar 2010, 11:42:54 EST by Rose Clements on behalf of Faculty Of Engineering, Architecture & Info Tech