We propose an extension to Boltzmann BGK equation for diatomic gases. The model satisfies the $H$ theorem and accurately recovers the compressible hydrodynamics for a diatomic gas as its macroscopic limit. The collision term is modified to account for the rotational energy and supplemented with an equation representing the evolution of the rotational energy. We demonstrate the accuracy of lattice Boltzmann implementation of the proposed model by calculating the speed of sound in a diatomic medium.

中文翻译：

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扩展的BGK模型用于双原子气体

我们建议扩展Boltzmann BGK方程用于双原子气体。该模型满足$H$定理并准确地恢复了双原子气体的可压缩流体力学作为其宏观极限。修改了碰撞项以考虑旋转能量，并补充了代表旋转能量演变的方程式。通过计算双原子介质中的声速，我们证明了提出的模型的格子Boltzmann实现的准确性。