Journal of Statistical Physics. Vol. 91, Nos. 1/2. 1998. p. 327-341.
Models of discrete velocity gases have been used for a long time, but only in the last few years have they become a tool to construct sequences converging to solutions of the Boltzmann equation. It appears that the case of mixtures has been rarely considered and only a couple of models, which are trivial in a sense to be explained in this paper, have been introduced. Here we thoroughly investigate the matter, and supply examples of models with both finitely and infinitely many velocities.