We present a relativistic Shakhov-type generalization of the Anderson-Witting relaxation time model for the Boltzmann collision integral to modify the ratio of momentum diffusivity to thermal diffusivity. This is achieved by modifying the path on which the single particle distribution function approaches local equilibrium by constructing an intermediate Shakhov-type distribution similar to the 14-moment approximation of Israel and Stewart. We illustrate the effectiveness of this model in case of the Bjorken expansion of an ideal gas of massive particles and the damping of longitudinal waves through an ultrarelativistic ideal gas.

中文翻译：

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相对论运动论和二阶流体动力学中弛豫时间近似的Shakhov型推广


我们提出了玻尔兹曼碰撞积分的 Anderson-Witting 弛豫时间模型的相对论 Shakhov 型推广，以修改动量扩散率与热扩散率的比率。这是通过构建类似于 Israel 和 Stewart 的 14 矩近似的中间 Shakhov 型分布来修改单粒子分布函数接近局部平衡的路径来实现的。我们说明了该模型在大质量粒子理想气体的比约肯膨胀和超相对论理想气体的纵波阻尼的情况下的有效性。