RELAXATION SCHEMES FOR NONLINEAR KINETIC-EQUATIONS

A class of numerical schemes for nonlinear kinetic equations oi Boltzm ann type is described. Following Wild's approach, the solution is repr esented as a power series with parameter depending exponentially on th e Knudsen number. This permits us to derive accurate and stable time d iscretizations for all ranges of the mean free path. These schemes pre serve the main physical properties: positivity, conservation of mass, momentum, and energy Moreover, for some particular models, the entropy property is also shown to hold.