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Journal of Statistical Physics

, Volume 99, Issue 3–4, pp 967–991 | Cite as

A Class of Planar Discrete Velocity Models for Gas Mixtures

  • Henri Cornille
  • Carlo Cercignani
Article

Abstract

We present a method for the construction of a simple class of physically acceptable planar discrete velocity models (DVMs) for binary gas mixtures. We want five conservation laws (no more, no less) with binary collisions. We first consider a collision with a particle at rest and different possibilities for the three other particles. We associate other particles and find semisymmetric qvi models with q=7, 9, 11, 13 and 15, symmetric with respect to the two coordinate axes, but not to an exchange between the two axes. In order to avoid “spurious” mass conservation relations for the species without particle at rest, we find, for the two coordinate axes, that the tips of the momenta of the particles must be on two intervals parallel to one axis with opposite values on the other. There remain some physically acceptable q=9 (the smallest) and 11, 13, 15 models (adding multiple collisions for some others). Second, we construct the associated symmetric models qvi^qvi, which are superpositions of the qvi model and another ^qvi, rotated by π/2. The possible previous defect of the spurious mass invariant for qvi is transmitted to the symmetric one. We explain another defect coming from qvi and ^qvi having only one common particle, then “spurious” invariants exist for the momentum conservations along the two axes. We get four physically acceptable symmetric 17vi (and three intermediate semisymmetric 13vi models) and one 25vi model superposition of two 11vi and two 15vi models (other acceptable symmetric 11vi, 13vi, and 25vi models exist with multiple collisions).

discrete velocity models mixtures collision invariants 

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REFERENCES

  1. 1.
    A. V. Bobylev and C. Cercignani, Discrete velocity models for mixtures, J. Stat. Phys. 91:327–342 (1998).Google Scholar
  2. 2.
    C. Cercignani and A. V. Bobylev, Discrete velocity models: the case of mixtures, Transp. Th. Stat. Phys. (to appear, 1999); A. V. Bobylev and C. Cercignani, J. Stat. Phys. 91:327 (1998); “Discrete Velocity Models for Mixtures, ” 21st International Symposium on RGD Vol I, pp. 71-77.Google Scholar
  3. 3.
    C. Cercignani and H. Cornille, Shock waves for a discrete velocity gas mixture, J. Stat. Phys. 99:115–140 (2000).Google Scholar
  4. 4.
    A. V. Bobylev and C. Cercignani, DVM models without non-physical invariants, J. Stat. Phys. 97:677–686 (1999).Google Scholar
  5. 5.
    C. Cercignani, The Boltzmann Equation and its Applications, Vol. 67 (Springer-Verlag, Applied Mathematical Sciences, 1987).Google Scholar
  6. 6.
    R. Monaco and L. Preziosi, Fluid Dynamic Applications of the Discrete Boltzmann Equation (World Scientific, Singapore, 1991).Google Scholar
  7. 7.
    H. Cornille and C. Cercignani, On a class of planar discrete velocity models for gas mixture, WASCOM-99 (Vulcano, June 1999).Google Scholar

Copyright information

© Plenum Publishing Corporation 2000

Authors and Affiliations

  • Henri Cornille
    • 1
  • Carlo Cercignani
    • 2
  1. 1.Service de Physique Théorique, CE SaclayGif-sur-YvetteFrance
  2. 2.Dipartimento di MatematicaPolitecnico di MilanoMilanItaly

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