Six-field extended thermodynamics models representing molecular energy exchange in a dense polyatomic gas

In the framework of extended thermodynamics, we present three models of a dense polyatomic gases with 6 independent fields. The three models, respectively, represent the relaxation process due to the different molecular energy exchange among the translational, rotational and vibrational energies of a molecule. The characteristic velocities, the local exceptionality and the Maxwellian iteration are also studied. As an example, we study the six-field models of a van der Waals fluid.