Slip flow over structured surfaces with entrapped microbubbles
Slip flow over structured surfaces with entrapped microbubbles
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DOI：
10.1103/physrevlett.100.246001
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发表时间：
2008-06-20
影响因子：
8.6
通讯作者：
Harting, Jens
中科院分区：
文献类型：
--
作者：
Hyvaluoma, Jari;Harting, Jens
在疏水表面上，粗糙度可能导致向超疏水状态的转变，其中表面处的气泡可能对检测到的滑动具有强烈影响。我们提出了两相格子玻尔兹曼模拟的Couette流结构表面与附着的气泡。即使气泡增加了通道的光滑表面，但由于粗糙度增加，它们也会导致出现负滑动。所使用的模拟方法允许气泡由于粘性应力而变形。我们发现，检测到的滑移随着剪切速率的增加而减少，这与最近的一些实验结果相反，这些实验表明气泡变形不能解释这些实验。讨论了气泡表面在微流控器件中的可能应用。
On hydrophobic surfaces, roughness may lead to a transition to a superhydrophobic state, where gas bubbles at the surface can have a strong impact on a detected slip. We present two-phase lattice Boltzmann simulations of a Couette flow over structured surfaces with attached gas bubbles. Even though the bubbles add slippery surfaces to the channel, they can cause negative slip to appear due to the increased roughness. The simulation method used allows the bubbles to deform due to viscous stresses. We find a decrease of the detected slip with increasing shear rate which is in contrast to some recent experimental results implicating that bubble deformation cannot account for these experiments. Possible applications of bubble surfaces in microfluidic devices are discussed.