Institute for Computational Physics, University of Stuttgart, Pfaffenwaldring 27, 70569 Stuttgart, Germany.
Phys Rev Lett. 2010 Jul 2;105(1):016001. doi: 10.1103/PhysRevLett.105.016001. Epub 2010 Jun 30.
We report results of lattice Boltzmann simulations of a high-speed drainage of liquid films squeezed between a smooth sphere and a randomly rough plane. A significant decrease in the hydrodynamic resistance force as compared with that predicted for two smooth surfaces is observed. However, this force reduction does not represent slippage. The computed force is exactly the same as that between equivalent smooth surfaces obeying no-slip boundary conditions, but located at an intermediate position between peaks and valleys of asperities. The shift in hydrodynamic thickness is shown to depend on the height and density of roughness elements. Our results do not support some previous experimental conclusions on a very large and shear-dependent boundary slip for similar systems.
我们报告了格子玻尔兹曼模拟在光滑球体和随机粗糙平面之间挤压的高速排液薄膜的结果。与预测的两个光滑表面相比，观察到水动力阻力显著降低。然而，这种力的减小并不代表滑移。计算得到的力与服从无滑移边界条件的等效光滑表面之间的力完全相同，但位于粗糙度峰谷之间的中间位置。水动力厚度的移动被证明取决于粗糙度元素的高度和密度。我们的结果不支持一些先前关于类似系统的非常大且剪切相关的边界滑移的实验结论。
