论文标题
基于正交的晶格Boltzmann模型，用于非平衡密集气流
Quadrature-based Lattice Boltzmann model for non-equilibrium dense gas flows
论文作者
论文摘要
由于气体分子的大小与平均分子间距离相当，因此玻尔兹曼方程变得无效。 Enskog碰撞操作员提供了更好的描述，该操作员考虑了气体分子的有限尺寸。这一扩展意味着非本地碰撞以及碰撞频率的增加，使其在计算上的解决方案昂贵。在这项工作中使用了Enskog碰撞操作员的近似值，表示简化的Enskog碰撞操作员，用于开发一种基于正交的晶格玻璃体模型，用于非理想的元素密集气体。 Shakhov碰撞期限是为了微调PrandTL编号。该动力学模型被证明能够解决密集气体的非平衡流问题，即声波和冲击波传播。将结果系统地与更准确但计算密集的粒子方法的结果进行比较。本文中引入的模型显示出对流体的较小至中等密度的良好精度（定义为分子直径与平均自由路径的比率），并且由于计算时间的效率，它适用于实际应用。
The Boltzmann equation becomes invalid as the size of gas molecules is comparable with the average intermolecular distance. A better description is provided by the Enskog collision operator, which takes into account the finite size of gas molecules. This extension implies non-local collisions as well as an increase in collision frequency, making it computationally expensive to solve. An approximation of the Enskog collision operator, denoted the simplified Enskog collision operator, is used in this work to develop a quadrature-based Lattice Boltzmann model for non-ideal monatomic dense gases. The Shakhov collision term is implemented in order to fine-tune the Prandtl number. This kinetic model is shown to be able to tackle non-equilibrium flow problems of dense gases, namely the sound wave and the shock wave propagation. The results are compared systematically with the results of the more accurate but computationally intensive particle method of solving the Enskog equation. The model introduced in this paper is shown to have good accuracy for small to moderate denseness of the fluid (defined as the ratio of the molecular diameter to the mean free path) and, due to the efficiency in terms of the computational time, it is suitable for practical applications.
