We perform equilibrium molecular dynamics simulations for nanoscale fluids confined between two parallel walls and investigate how the autocorrelation function of force acting on one wall is related to the slip length. We demonstrate that for atomically smooth surfaces, the autocorrelation function is accurately described by linearized fluctuating hydrodynamics (LFH). Excellent agreement between the simulation and the LFH solution is found over a wide range of scales, specifically, from the timescale of fluid relaxation even to that of molecular motion. Fitting the simulation data yields a reasonable estimation of the slip length. We show that LFH provides a starting point for examining the relationship between the slip length and the force fluctuations.

中文翻译：

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基于波动流体力学的滑移长度平衡测量方法

我们对限制在两个平行壁之间的纳米级流体进行平衡分子动力学模拟，并研究作用在一个壁上的力的自相关函数如何与滑移长度相关。我们证明，对于原子光滑的表面，自相关函数可以通过线性波动流体动力学（LFH）精确描述。在很宽的范围内，特别是从流体弛豫的时间尺度到分子运动的时间尺度，都发现了仿真与LFH解决方案之间的出色一致性。拟合仿真数据可得出滑移长度的合理估计值。我们表明，LFH为检查滑动长度和力波动之间的关系提供了一个起点。