Effects of the slip wall on the drag and coherent structures of turbulent boundary layer
Effects of the slip wall on the drag and coherent structures of turbulent boundary layer
复制标题
滑移壁对湍流边界层阻力和相干结构的影响
DOI：
10.1007/s10409-021-01092-0
复制
发表时间：
2021
影响因子：
3.5
通讯作者：
Jiang Nan
中科院分区：
文献类型：
--
作者：
Wang Xinwei;Wang Yufei;Tian Haiping;Jiang Nan
利用时间分辨粒子图像速度场仪（TRPIV）对光滑表面和各向异性超疏水表面上的湍流边界层（TBL）进行了对比实验。用单像素分辨率系综相关法计算的粘性子层速度与壁面摩擦速度拟合较好。在此基础上，得到了SH面上的减阻率为17%，滑移速度为0.0119 m/s，滑移长度为。在降阶流场的主要模态中，SH表面的波包结构变得“直立”。这种运动中的大尺度结构在瞬时场中也能找到。根据相关性的统计结果发现，滑移壁导致结构不同位置对流速度的变化，从而导致结构形态的变化和剪切层的畸变。
A comparative experiment by time-resolved particle image velocimetry (TRPIV) of the turbulent boundary layer (TBL) over a smooth surface and an anisotropy superhydrophobic (SH) surface was carried out in an open-surface recirculating water channel at. The wall friction velocity is fitted well from the velocity of the viscous sublayer calculated by the Single-pixel resolution ensemble correlation (SPEC). After that, a drag reduction rate of 17%, a slip velocity of 0.0119 m/s, and a slip length ofare obtained over the SH surface. In the main modes of the reduced-order flow fields, the wave packet structures over the SH surface become “upright”. Such large-scale structures in motion are also found in the instantaneous field. According to the statistical results of the correlation, it is found that the slip wall leads to the change of the convection velocity at different positions of the structure, which leads to the change of structure morphology and the distortion of the shear layer.