A model for polyatomic gases with hyperbolicity and H-theorem satis- fied up to whatever order

  • Sebastiano Pennisi Dipartimento di Matematica ed Informatica, Universitá di Cagliari
Keywords: relativistic fluids; relativistic BGK model; rarefied polyatomic gases


A relativistic model for polyatomic gases with an arbitrary but fixed number of moments is well- known in the literature. The model’s balance equations have symmetric hyperbolic form in their left-hand sides because the tensors that derivated with respect to xα are gradients of a 4-potential. Here, the symmetric form and a 4-potential are obtained for their right-hand side also, i.e., the production terms. Moreover, this will allow us to prove the H-theorem up to whatever order, while in other articles present in the literature, this result was achieved only up to the second order concerning equilibrium. These obtained results can be derived by either following the Eckart approach or the Landau-Lifshitz one.


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Original Research Article