论文标题
深入的表征和分析简单剪切流在定期排列的微柱上，I。流体惯性的影响
In-depth characterization and analysis of simple shear flows over regularly arranged micro pillars, I. Effect of fluid inertia
论文作者
论文摘要
通过高保真数值模拟，已经研究了经常布置的微支柱上的简单剪切流。待解决的基本问题包括微柱四边形阵列上的简单剪切流的特征，流体惯性对基本流动模式的影响以及复杂表面摩擦的分解。结果表明，流动的特征是在流向邻近支柱之间的间隙中的一系列微观循环涡流。微观涡流的再循环和从支柱尖端攀登的高架流动的振荡创造了局部流量对流。在较小的雷诺数下，流体惯性很弱，流动模式在支柱中心对称。当雷诺数足够大时，流体惯性会生效并破坏对称模式。高架流向下倾斜，形成了支柱阵列上方的流体流量与微支柱之间的空间中的流动之间的螺旋长距离对流。局部对流和远程对流构成了壁正常方向的运输机制。在微观结构的墙壁上，总摩擦包括由于流动剪切和柱表面的流动压力以及由于底部表面上的流动剪切而引起的底平面的反作用力引起的微柱的反作用力。对于较大的雷诺数，流体惯性可防止流体沿微柱的弯曲表面流动，并减少由于流动剪切而引起的柱子反应力的等效剪切应力。同时，流体惯性使高架流动更强烈地影响微柱的迎风侧，因此增加了由于流动压力而导致的柱反应力的等效剪切应力。
Through high-fidelity numerical simulation, the simple shear flow over regularly arranged micro pillars has been investigated. The essential issues to be addressed include the characteristics of a simple shear flow over quadrilateral array of micro pillars, the effect of fluid inertia on the basic flow pattern, and the decomposition of the complex surface friction. The results show that the flow is characterized by a series of microscale recirculating eddies in the gaps between the streamwise neighboring pillars. The recirculation of the micro eddies and the oscillation of the overhead flow climbing over the pillar tips create a local flow advection. At smaller Reynolds number, the fluid inertia is weak and the flow patterns are symmetrical about the pillar center. When the Reynolds number is sufficiently large, the fluid inertia takes effect and breaks the symmetrical patterns. The overhead flow tilts downward, forming a spiral long-range advection between the fluid flow above pillar array and the flow in the spaces among micro pillars. The local advection and long-range advection constitute the transport mechanism in wall-normal direction. On micro-structured walls, the total friction includes the reaction forces of micro pillars due to flow shear and flow pressure at pillar surfaces and the reaction force of bottom plane due to flow shear on bottom surface. For larger Reynolds numbers, fluid inertia prevents the fluid from flowing along the curved surface of micro pillars and reduces the equivalent shear stress of the pillar reaction force due to flow shear. At the same time, the fluid inertia makes the overhead flow impact the windward side of micro pillars more strongly and therefore increases the equivalent shear stress of the pillar reaction force due to flow pressure.
