Some alternative methods for hydrodynamic closures to dissipative kinetic models

Two different strategies for deriving hydrodynamic equations for dissipative kinetic models are presented and discussed. The homogeneity scaling approach, not very well-known in the physical literature, is expanded and applied to different show-cases in several applications. Then, we show that this strategy may fail, as it occurs for a thermalized granular gas in a host medium, in which case the problem can be dealt with by resorting to classical moment closure methods. © 2009 EDP Sciences and Springer.