DSMC Convergence Behavior for Fourier Flow
Abstract
The convergence behavior of Bird's Direct Simulation Monte Carlo (DSMC) method is explored for near-continuum, one-dimensional Fourier flow. An argon-like, hard-sphere gas is confined between two parallel, fully accommodating, motionless walls of unequal temperature. The simulations are performed using a one-dimensional code based on Bird's DSMC prescription. The convergence metric is taken as the ratio of the DSMC-calculated bulk thermal conductivity to the infinite-approximation, Chapman-Enskog (CE) theoretical value. The convergence rate is monitored with respect to three parameters: time step, cell size, and number of computational molecules per cell. For a sufficiently large number of computational molecules, the DSMC discretization error is observed to decrease quadratically with time step and cell size, in good agreement with previous predictions based on Green-Kubo theory. When all three parameters are finite, the observed convergence behavior is complex. As numerical errors are systematically reduced, the DSMC-calculated conductivity is shown to approach the theoretical CE value to within 0.02%, showing that the present implementation of Bird's DSMC algorithm provides an excellent representation of continuum, CE heat conduction.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 13, 2005
- Accession Number
- ADA445983
Entities
People
- D. J. Radar
- J. R. Torczynski
- M. A. Gallis
- W. Wagner
Organizations
- Sandia National Laboratories