Tunable-slip boundaries for coarse-grained simulations of fluid flow
Tunable-slip boundaries for coarse-grained simulations of fluid flow
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DOI：
10.1140/epje/i2007-10311-4
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发表时间：
2008-05-01
影响因子：
1.8
通讯作者：
Schmid, F.
中科院分区：
文献类型：
--
作者：
Smiatek, J.;Allen, M. P.;Schmid, F.
在微米和纳米尺度上，经典的流体动力学边界条件，如无滑移条件不再适用。相反，流动剖面在表面处表现出“滑移”，其特征在于有限的滑移长度（部分滑移）。我们提出了一种新的，系统的方式来实现任意滑移长度的粗粒度计算机模拟的部分滑移边界条件。其主要思想是通过空间变化的有效粘性力来表示复杂的微观界面结构。由此产生的滑移长度的分析方程可以推导出平面和曲面。与DPD（耗散粒子动力学）流体的计算机模拟的比较表明，该表达式是有效的从全滑移到无滑移。
On the micro- and nanoscale, classical hydrodynamic boundary conditions such as the no-slip condition no longer apply. Instead, the flow profiles exhibit "slip" at the surface, which is characterized by a finite slip length (partial slip). We present a new, systematic way of implementing partial-slip boundary conditions with arbitrary slip length in coarse-grained computer simulations. The main idea is to represent the complex microscopic interface structure by a spatially varying effective viscous force. An analytical equation for the resulting slip length can be derived for planar and for curved surfaces. The comparison with computer simulations of a DPD (dissipative particle dynamics) fluid shows that this expression is valid from full slip to no slip.