A semi-analytical model is presented for pressure-driven flow through a channel, where local pressure loss is incurred at a sudden change in the boundary condition: from no-slip to partial-slip. Assuming low-Reynolds-number incompressible flow and periodic stick–slip wall patterning, the problems for parallel-plate and circular channels are solved using the methods of eigenfunction expansion and point match. The present study aims to examine in detail how the flow will evolve, on passing through the cross section at which the change in the slip condition occurs, from a no-slip parabolic profile to a less sheared profile with a boundary slip. The present problem is germane to, among other applications, flow through a channel bounded by superhydrophobic surfaces, which intrinsically comprise an array of no-slip and partial-slip segments. Results are presented to show that the sudden change in the boundary condition will result in additional resistance to the flow. Near the point on the wall where a slip cha...

中文翻译：

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边界条件从无滑移到部分滑移的突然变化导致通道流动中的压力损失

提出了压力驱动流经通道的半解析模型，其中在边界条件突然变化时会产生局部压力损失：从无滑移到部分滑移。假设低雷诺数不可压缩流动和周期性粘滑壁模式，平行板和圆形通道的问题使用特征函数展开和点匹配的方法解决。本研究旨在详细研究流动将如何在穿过发生滑移条件变化的横截面时从无滑移抛物线轮廓演变为具有边界滑移的剪切力较小的轮廓。目前的问题与流经以超疏水表面为边界的通道密切相关，该通道本质上包括一系列无滑动和部分滑动部分。结果表明边界条件的突然变化将导致对流动的额外阻力。靠近墙壁上有一个滑梯的点...