Thin-Film Fluid Flows over Microdecorated Surfaces: Observation of Polygonal Hydraulic Jumps
Thin-Film Fluid Flows over Microdecorated Surfaces: Observation of Polygonal Hydraulic Jumps
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DOI：
10.1103/physrevlett.102.194503
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发表时间：
2009-05-15
影响因子：
8.6
通讯作者：
Stone, Howard A.
中科院分区：
文献类型：
--
作者：
Dressaire, Emilie;Courbin, Laurent;Stone, Howard A.
流动在粗糙基材上的液体薄膜受到大小与薄膜厚度相当的凸起的影响。我们研究了由射流对微米尺寸的常规阵列的冲击所驱动的流。我们发现地形改变了观测到的水力跳跃的大小和形状：除了圆形跳跃外，我们还获得了各种稳定的多边形形状。我们通过考虑穿过织构的泄漏流及其上方的自由表面流，以及考虑到织构对称性的有效滑移边界条件来合理化我们的结果。该模型与我们的实验非常吻合，并且允许我们考虑流动特性和粗糙度参数之间的相互作用，该模型适用于许多其他薄膜结构。
Liquid films flowing over rough substrates are influenced by asperities whose sizes are comparable to the film thickness. We investigate flows driven by jet impact on a regular array of micron-size posts. We show that the topography modifies the size and the shape of the observed hydraulic jumps: in addition to circular jumps, we obtain a variety of stable polygonal shapes. We rationalize our results by considering a leakage flow through the texture and the free-surface flow above it, coupled by an effective slip boundary condition accounting for the symmetry of the texture. This model is in good agreement with our experiments and allows us to account for the interplay between flow properties and roughness parameters, which has applicability in many other thin-film configurations.