Two routes from the Boltzmann equation to compressible flow of polyatomic gases

P. J. Dellar (2008) Two routes from the Boltzmann equation to compressible flow of polyatomic gases Progress in Computational Fluid Dynamics 8 84-96

Reprint available (TwoRoutesPoly.pdf 322K)


Abstract

This paper presents a systematic approach to simulating compressible flow of polyatomic gases using the Boltzmann equation for a discrete set of particle velocities. We derive the complete system of moment equations needed to recover the Navier-Stokes-Fourier equations. One may either circumvent the usual relation between pressure and internal energy density by assigning additional energies to the particles, or introduce an entirely separate set of particle distribution functions to simulate the macroscopic energy equation. The latter permits the use of longer timesteps, and may generalise more easily to multiple space dimensions. However, the momentum and energy equations must be coupled to obtain correct viscous heating for realistic values of the Prandtl number. Numerical experiments are presented for the standard one dimensional Sod shock tube benchmark for monatomic and diatomic gases using both unified 7 velocity and split 4 + 3 velocity formulations.


@article{Dellar08poly,
  Author    = {Dellar, P. J.},
  Title     = {Two routes from the Boltzmann equation to compressible flow of polyatomic gases},
  Journal   = {Progress in CFD},
  Year      = {2008},
  Volume    = {8},
  Pages     = {94--96},
  DOI       = {doi:10.1504/PCFD.2008.018081},
  URL       = {http://www.inderscience.com/link.php?id=18081}
}