On the boundary slip of fluid flow
On the boundary slip of fluid flow
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DOI：
10.1360/03yw0304
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发表时间：
2005-04
期刊：
影响因子：
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通讯作者：
Cheng-wei Wu;G. Ma
中科院分区：
文献类型：
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作者：
Cheng-wei Wu;G. Ma
本文提出了一个应力控制的边界滑移模型，并预测了平行滑动板或接近光滑平面的球体系统中的流固界面滑移。数值模拟结果与已有的实验观测结果吻合得很好。该模型假定存在一个极限剪应力。当表面剪应力小于极限剪应力时，不发生滑移;当表面剪应力等于极限剪应力时，发生滑移;当两个压缩表面具有相同的滑移特性时，边界滑移会显著降低动水压力。最后，水动力达到饱和状态，几乎不再减小。与无滑移解相比，有滑移时的水动力减小了两个数量级以上。然而，当挤压表面具有不同的滑移特性时，流体动压力主要由具有较小的表面极限剪应力的表面控制，并且与具有相同滑移特性的两个表面的情况相比，流体动压力减小得更慢。即使当其中一个表面的极限剪应力为零时，仍然存在相当大的水动力。
This paper presents a stress controlled boundary slip model and predicts the fluid-solid interface slip in a system of parallel sliding plates or a sphere approaching a smooth plane. The numerical simulation results are in striking agreement with the existing experimental observations. This model assumes that there is a limiting shear stress. No slip occurs if the surface shear stress is smaller than the limiting shear stress, and slip occurs when the surface shear stress equals it. It is found that boundary slip dramatically decreases the hydrodynamic pressure if the two squeezed surfaces have the same slip property. Finally, the hydrodynamic force reaches a saturation status and almost does not decrease any more. Compared with the no-slip solution, hydrodynamic force is found to decrease by over two orders in the case of boundary slip. When the squeezed surfaces have different slip properties, however, the hydrodynamic pressure is mainly controlled by the surface having a smaller surface limiting shear stress, and reduces more slowly compared with the case of two surfaces having the same slip property. Even when one of the surfaces has a zero surface limiting shear stress, a considerable hydrodynamic force still exists.