Discrete velocity Boltzmann equation in the plane: stationary solutions

Artikel i vetenskaplig tidskrift, 2022

The paper proves existence of stationary mild solutions for normal discrete velocity Toltzmann eations in the plane with no pair of interacting velocities being parallel. The ingoing boundary values are given. A key property is L1 compactness of integrated collision frequencyfor a sequence of approximations. It is proven using the Kolmogorov Riesz theorem, kwhich replaces kL1 compactness of velocity averages in the continuous velocity case, but not available for discrete velocities.