title: Structure of velocity distributions in shock waves in granular gases with extension to molecular gases.
abstract: Velocity distributions in normal shock waves obtained in dilute granular flows are studied. These distributions cannot be described by a simple functional shape and are believed to be bimodal. Our results show that these distributions are not strictly bimodal but a trimodal distribution is shown to be sufficient. The usual Mott-Smith bimodal description of these distributions, developed for molecular gases, and based on the coexistence of two subpopulations (a supersonic and a subsonic population) in the shock front, can be modified by adding a third subpopulation. Our experiments show that this additional population results from collisions between the supersonic and subsonic subpopulations. We propose a simple approach incorporating the role of this third intermediate population to model the measured probability distributions and apply it to granular shocks as well as shocks in molecular gases.
authors.affiliation: Université de Bordeaux, Laboratoire Ondes et Matière d'Aquitaine, UMR 5798 U. Bordeaux/CNRS, 351 cours de la Libération, 33405 Talence, France.
authors.forename: A
authors.initials: A
authors.lastname: Vilquin
authors.affiliation: Université de Bordeaux, Laboratoire Ondes et Matière d'Aquitaine, UMR 5798 U. Bordeaux/CNRS, 351 cours de la Libération, 33405 Talence, France.
authors.forename: J F
authors.initials: JF
authors.lastname: Boudet
authors.affiliation: Université de Bordeaux, Laboratoire Ondes et Matière d'Aquitaine, UMR 5798 U. Bordeaux/CNRS, 351 cours de la Libération, 33405 Talence, France.
authors.forename: H
authors.initials: H
authors.lastname: Kellay