Nonlinear ET₇ Theory with Molecular Rotational and Vibrational Modes

Abstract

In Chap. 8, we have established the ET₁₅ theory of rarefied polyatomic gases where molecular rotational and vibrational modes are taken into account individually. Thereby, compared with the ET₁₄ theory, we have obtained a more refined version with a wider applicability range. And, in Chaps. 12 and 13, we have constructed the nonlinear ET₆ theory by ignoring the shear viscosity and heat conductivity. The features of the dynamic pressure can be highlighted by using the ET₆ theory. Similar to the relationship between ET₁₄ and ET₁₅, in this chapter, we derive the ET₇ theory of rarefied polyatomic gas with molecular rotational and vibrational modes by ignoring the shear viscosity and heat conductivity as a generalization of the ET₆ theory. In this case, as in ET₁₅, we need a triple hierarchy of the moment system. The system of balance equations is closed via the maximum entropy principle (MEP). Three different types of the production term in the system, which are studied in Chap. 8 on the basis of the generalized BGK model for the collision term in the Boltzmann equation, are also adopted. Some characteristic features of the ET₇ theory are discussed.