论文标题

瞬态流体动力学的逆雷诺义优势方法

Inverse-Reynolds-Dominance approach to transient fluid dynamics

论文作者

Wagner, David, Palermo, Andrea, Ambruş, Victor E.

论文摘要

我们考虑了从动力学理论中二阶相对论耗散性流体动力学中衍生的大量粘性压力,扩散电流和剪切张量的演化方程。通过将高阶时刻直接与耗散数量匹配,所有术语在Knudsen Number number n of Vanish中仅留下$ \ Mathcal {o}(\ textrm {\ textrm {re}^{ - 1} { - 1} { - 1} \ textrm {kn})方程式,其中$ \ textrm {re}^{ - 1} $是逆雷诺数。因此,我们将此方案称为逆雷诺德占主导地位(IRED)方法。剩余的(非变化)运输系数可以仅根据碰撞矩阵的逆获得。该过程明确固定了耗散量的放松时间,这些放松时间与碰撞矩阵倒数的特征值不再相关。特别是,我们发现与高阶矩的相对应随着其顺序的增加而增长的放松时间,从而与\ textit {scales sakity}范式相矛盾。证明了与标准DNMR方法的正式(最高二阶)等效性,并且建立了IRED运输系数与常规DNMR之间的连接。

We consider the evolution equations for the bulk viscous pressure, diffusion current and shear tensor derived within second-order relativistic dissipative hydrodynamics from kinetic theory. By matching the higher order moments directly to the dissipative quantities, all terms which are of second order in the Knudsen number Kn vanish, leaving only terms of order $\mathcal{O}(\textrm{Re}^{-1} \textrm{Kn})$ and $\mathcal{O}(\textrm{Re}^{-2})$ in the relaxation equations, where $\textrm{Re}^{-1}$ is the inverse Reynolds number. We therefore refer to this scheme as the Inverse-Reynolds-Dominance (IReD) approach. The remaining (non-vanishing) transport coefficients can be obtained exclusively in terms of the inverse of the collision matrix. This procedure fixes unambiguously the relaxation times of the dissipative quantities, which are no longer related to the eigenvalues of the inverse of the collision matrix. In particular, we find that the relaxation times corresponding to higher-order moments grow as their order increases, thereby contradicting the \textit{separation of scales} paradigm. The formal (up to second order) equivalence with the standard DNMR approach is proven and the connection between the IReD transport coefficients and the usual DNMR ones is established.

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