Molecular extended thermodynamics of rarefied polyatomic gases and wave velocities for increasing number of moments

The characteristic velocities of the emerging hyperbolic system of differential equations are compared to those obtained for monatomic gases and the lower bound estimate for the maximum equilibrium characteristic velocity established for monatomic gases (characterized by only one hierarchy for moments with truncation order of moments N) by Boillat and Ruggeri (1997)λ(N)E,maxc0⩾65(N−12),(c0=53kmT) is proven to hold also for rarefied polyatomic gases independently from the degrees of freedom of a molecule.