An ES-BGK model for vibrational polyatomic gases

Y Dauvois (1) , J. Mathiaud (2, 3) , Luc Mieussens (4)

1 CEA - Commissariat à l'énergie atomique et aux énergies alternatives
2 CEA-CESTA - Commissariat à l'Energie Atomique et aux Energies Alternatives
3 CELIA - Centre d'Etudes Lasers Intenses et Applications
4 IMB - Institut de Mathématiques de Bordeaux

We propose an extension of the Ellipsoidal-Statistical BGK model to account for discrete levels of vibrational energy in a rarefied polyatomic gas. This model satisfies an H-theorem and contains parameters that allow to fit almost arbitrary values for the Prandtl number and the relaxation times of rotational and vibrational energies. With the reduced distribution technique , this model can be reduced to a three distribution system that could be used to simulate polyatomic gases with rotational and vibrational energy for a computational cost close to that of a simple monoatomic gas.

Domaines: Equations aux dérivées partielles [math.AP]

Y Dauvois, J. Mathiaud, Luc Mieussens. An ES-BGK model for vibrational polyatomic gases. 2020. ⟨hal-02887717v1⟩