中文摘要：

自然给我们看了在海洋的快游泳的鲨鱼的皮肤的微观结构能减少皮肤磨擦由于著名鲨鱼皮效果拖。在现在的学习，在狂暴的边界层(TBL ) 的协调旋涡结构上的 shark-skin-inspired riblets 的效果被调查。这在 190 的一个磨擦雷纳兹数字在拖减少 riblets 的一个丙烯酸的盘子上在隧道流动借助于 tomographic 粒子图象 velocimetry (TPIV ) 被做大小。在拖减少 riblets 上的狂暴的流动被平面解决时间的粒子图象 velocimetry (TRPIV ) 验证系统开始，然后 TPIV 大小被执行。二维(2D ) 有拖减小的试验性的结果约 4.81 评价 ?% 在有 peak-to-peak 间距 \ 的三角 riblets 上清楚地是可见的(s ^{+}\) 14，从拖减少表演显示在 TBL 以内的缓冲区层变厚；对数的法律区域向上变了并且雷纳兹砍应力减少了。协调旋涡结构的 spanwise 涡度的空间拓扑的分布的比较通过切开方法的改进象限在不同墙正常高度提取了当时，证明 riblets 削弱 spanwise 涡度的振幅喷射( Q2 )并且扫( Q4 )事件发生在近的墙，特别地在 Q4 事件上有最大的效果。所谓的四极为在整个 TBL 的协调结构的统计模型被验证。同时，他们的空间有条件一般水准的拓扑的形状和协调旋涡在 overlying 总体上组织的四极的空间规模在 riblets 上的狂暴的流动被改变，建议 riblets 阻抑在由压抑爆炸事件( Q2 和 Q4 )的 TBL 的近墙、外部的部分的区域之间的动量和精力交换，从而减少皮肤磨擦拖。图形的摘要

英文摘要：

Nature has shown us that the microstructure of the skin of fast-swimming sharks in the ocean can reduce the skin friction drag due to the well-known shark-skin effect.In the present study,the effect of shark-skin-inspired riblets on coherent vortex structures in a turbulent boundary layer（TBL） is investigated.This is done by means of tomographic particle image velocimetry（TPIV） measurements in channel fl ws over an acrylic plate of drag-reducing riblets at a friction Reynolds number of 190.The turbulent fl ws over drag-reducing riblets are verifie by a planar time-resolved particle image velocimetry（TRPIV） system initially,and then the TPIV measurements are performed.Two-dimensional（2D） experimental results with a dragreduction rate of around 4.81% are clearly visible over triangle riblets with a peak-to-peak spacing s＋of 14,indicating from the drag-reducing performance that the buffer layer within the TBL has thickened;the logarithmic law region has shifted upward and the Reynolds shear stress decreased.A comparison of the spatial topological distributions of the spanwise vorticity of coherent vortex structures extracted at different wall-normal heights through the improved quadrant splitting method shows that riblets weaken the amplitudesof the spanwise vorticity when ejection（Q2） and sweep（Q4） events occur at the near wall,having the greatest effect on Q4 events in particular.The so-called quadrupole statistical model for coherent structures in the whole TBL is verified Meanwhile,their spatial conditional-averaged topological shapes and the spatial scales of quadrupole coherent vortex structures as a whole in the overlying turbulent fl w over riblets are changed,suggesting that the riblets dampen the momentum and energy exchange between the regions of near-wall and outer portion of the TBL by depressing the bursting events（Q2 and Q4）,thereby reducing the skin friction drag.