Nonequilibrium Shear Viscosity Computations with Langevin Dynamics
Nonequilibrium Shear Viscosity Computations with Langevin Dynamics
复制标题
使用 Langevin Dynamics 进行非平衡剪切粘度计算
DOI：
10.1137/110836237
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发表时间：
2011
期刊：
影响因子：
--
通讯作者：
G. Stoltz
中科院分区：
文献类型：
--
作者：
R. Joubaud;G. Stoltz
本文研究了非平衡Langevin动力学的数学性质，该动力学可用于估计系统的剪切粘度。更确切地说，我们证明了一个线性响应的结果，使我们能够在非平衡稳态系统的平衡正则期望的平均值。然后，我们写一个本地的平均纵向速度的流体守恒定律，并显示如何在一些封闭近似下，粘度可以从这个配置文件中提取。最后，我们描述的渐近行为的速度分布，在限制的横向或纵向摩擦趋于无穷大。一些数值例子的理论结果也被提出。
We study the mathematical properties of a nonequilibrium Langevin dynamics which can be used to estimate the shear viscosity of a system. More precisely, we prove a linear response result which allows us to relate averages over the nonequilibrium stationary state of the system to equilibrium canonical expectations. We then write a local conservation law for the average longitudinal velocity of the fluid and show how, under some closure approximation, the viscosity can be extracted from this profile. We finally characterize the asymptotic behavior of the velocity profile, in the limit where either the transverse or the longitudinal friction goes to infinity. Some numerical illustrations of the theoretical results are also presented.