Stokes resistance of a solid cylinder near a superhydrophobic surface. Part 1. Grooves perpendicular to cylinder axis
Stokes resistance of a solid cylinder near a superhydrophobic surface. Part 1. Grooves perpendicular to cylinder axis
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超疏水表面附近实心圆柱体的斯托克斯阻力。
DOI：
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发表时间：
2019
影响因子：
3.7
通讯作者：
E. Yariv
中科院分区：
文献类型：
--
作者：
Ory Schnitzer;E. Yariv
一类重要的典型问题，是在量化的光滑的微结构超疏水表面的关注与相邻的固体，其尺寸是相对于微结构周期大的流体动力学载荷的计算。超疏水性的效果是最明显的，当后一段时间是可比的固体探针和超疏水表面之间的分离。我们解决了上述突出的限制，考虑一个简单的配置，其中超疏水表面是由周期性的凹槽阵列，其中气泡被困在Cassie状态，和固体是一个无限的圆柱体。在本部分中，我们考虑的情况下，凹槽垂直于圆柱体对齐，并允许三种模式的刚体运动：直线运动垂直于表面;直线运动平行于表面，在凹槽的方向;和角旋转的圆柱轴。在这种情况下，流动在平行于轴的方向上是周期性的。平均的小规模周期性产生一个修改后的润滑描述，其中小规模的细节封装在两个辅助的二维细胞的问题，分别描述压力和边界驱动的纵向流动通过一个不对称的矩形域，由一个复合表面从底部和一个无滑动表面从顶部。一旦积分通量和平均剪切应力与这些细胞的问题被计算为缓慢变化的细胞的几何形状的函数，所经历的圆柱体的水动力载荷被提供作为非线性函数的求积后者的分布在一个连续的细胞序列。
An important class of canonical problems that is employed in quantifying the slipperiness of microstructured superhydrophobic surfaces is concerned with the calculation of the hydrodynamic loads on adjacent solid bodies whose size is large relative to the microstructure period. The effect of superhydrophobicity is most pronounced when the latter period is comparable to the separation between the solid probe and the superhydrophobic surface. We address the above distinguished limit, considering a simple configuration where the superhydrophobic surface is formed by a periodically grooved array, in which air bubbles are trapped in a Cassie state, and the solid body is an infinite cylinder. In the present part, we consider the case where the grooves are aligned perpendicular to the cylinder and allow for three modes of rigid-body motion: rectilinear motion perpendicular to the surface; rectilinear motion parallel to the surface, in the groove direction; and angular rotation about the cylinder axis. In this scenario, the flow is periodic in the direction parallel to the axis. Averaging over the small-scale periodicity yields a modified lubrication description where the small-scale details are encapsulated in two auxiliary two-dimensional cell problems which respectively describe pressure- and boundary-driven longitudinal flow through an asymmetric rectangular domain, bounded by a compound surface from the bottom and a no-slip surface from the top. Once the integral flux and averaged shear stress associated with each of these cell problems are calculated as a function of the slowly varying cell geometry, the hydrodynamic loads experienced by the cylinder are provided as quadratures of nonlinear functions of the latter distributions over a continuous sequence of cells.
具有平坦或弱弯曲弯月面的对称超疏水通道有效滑移长度的精确公式
影响因子：
1.9
作者：
Marshall J
通讯作者：
Marshall J