On the degree of boundary slip over nonplanar surfaces
On the degree of boundary slip over nonplanar surfaces
复制标题
DOI：
10.1007/s10404-013-1183-z
复制
发表时间：
2013-04
影响因子：
2.8
通讯作者：
A. Dinler;R. Barber;D. Emerson;S. Stefanov;Kamil Orucoglu
中科院分区：
文献类型：
--
作者：
A. Dinler;R. Barber;D. Emerson;S. Stefanov;Kamil Orucoglu
多年来，在微/纳流体学中已经认识到流体-固体界面处的无滑移边界条件的崩溃。然而，表面的曲率和边界滑移的程度之间的关系还没有得到充分的理解。目前的研究表明，滑动的程度有效地取决于表面曲率，这是有一个相反的效果超过旋转凹，凸表面。结果表明，随着曲面曲率的增加，边界滑移在凹曲面上变得可以忽略不计，而在凸曲面上变得越来越重要。此外，边界滑移公式提出，可以准确地预测边界滑移凸，凹表面。这些公式被发现是在一个范围内的适应系数和边界曲率与DSMC数据非常好的协议。本研究解释了有趣的速度反演现象的机制，直到目前的研究，往往被错误地认为仅仅是边界曲率的影响。
The breakdown of the no-slip boundary condition at a fluid–solid interface has been recognized in micro/nanofluidics for many years. However, the relationship between the curvature of the surface and the degree of boundary slip has not been understood sufficiently well. The present study reveals that the degree of slip depends effectively on the surface curvature, which is having an opposing effect over rotating concave and convex surfaces. The results show that as surface curvature increases, the boundary slip becomes negligible over a concave surface, while it becomes increasingly important over a convex surface. In addition, boundary slip formulae are proposed that can accurately predict the boundary slips over convex and concave surfaces. These formulae are found to be in very good agreement with DSMC data for a range of accommodation coefficients and boundary curvatures. The present study then explains the mechanism of the intriguing phenomenon of velocity inversion which has, until the present study, often been mistakenly attributed solely to the effects of boundary curvature.