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.

中文翻译：

---

旋转和振动非平衡中多原子气体的ES-BGK模型

我们建议对椭球统计BGK模型进行扩展，以解决稀有多原子气体中振动能的离散水平。该模型满足H定理，并且包含的​​参数允许拟合普朗特数以及旋转和振动能量的弛豫时间的几乎任意值。利用简化的分配技术，可以将该模型简化为三个分配系统，该系统可用于模拟具有旋转和振动能的多原子气体，其计算成本接近简单单原子气体的计算成本。