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基于层析PIV的椭圆水翼近尾迹梢涡实验研究
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作者 赵航 佘文轩 +1 位作者 高琪 邵雪明 《实验流体力学》 CAS CSCD 北大核心 2022年第2期82-91,共10页
梢涡空化作为一种常见的空化现象,广泛存在于水力机械及船舶推进领域。梢涡空化初生与桨叶梢部的旋涡流动密切相关,因此有必要深入研究梢涡流场,揭示其流动特征与空化的内在联系。基于高时间解析度的层析PIV技术,在高速空泡水洞中对椭... 梢涡空化作为一种常见的空化现象,广泛存在于水力机械及船舶推进领域。梢涡空化初生与桨叶梢部的旋涡流动密切相关,因此有必要深入研究梢涡流场,揭示其流动特征与空化的内在联系。基于高时间解析度的层析PIV技术,在高速空泡水洞中对椭圆水翼的近尾迹梢涡流场开展了实验研究。结果表明:梢涡在近尾迹区域内存在明显的摆动现象,未考虑旋涡摆动的时间平均会在时均流场中引入额外的误差,因此在梢涡特性的定量研究中有必要滤除旋涡摆动的影响;在水翼脱落剪切层的作用下,涡核中心两侧的切向速度分布明显不对称,且在剪切层与涡核之间存在高速轴向流动区域;梢涡流场中的湍流脉动能量主要集中在涡核内部,且由法向、展向速度脉动主导。结合前人研究,发现法向、展向速度脉动是涡核内部湍流压力脉动的主要来源。 展开更多
关键词 椭圆水翼 梢涡 层析PIV 流场测量 涡运动
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Tomographic PIV investigation on coherent vortex structures over shark-skin-inspired drag-reducing riblets 被引量:8
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作者 Shao-Qiong Yang Shan Li +2 位作者 Hai-Ping Tian Qing-Yi Wang Nan Jiang 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2016年第2期284-294,共11页
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-insp... 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. 展开更多
关键词 Turbulent boundary layer(TBL) Coherent vortex structure Flow control Drag reduction Shark-skininspired riblet Tomographic particle image velocimetry(tpiv
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基于TPIV7.3嫩江流域达斡尔族文献数字化平台的构建 被引量:1
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作者 夏萍 张安达 +1 位作者 魏力更 王谨 《高师理科学刊》 2021年第5期27-30,共4页
嫩江流域达斡尔族文献数字化建设不仅能实现其文献的永久性保存,还可以有效地开发利用文献.分析了嫩江流域达斡尔族文献保存的现状,阐述了信息时代达斡尔族文献数字化的必要性,利用TPIV7.3构建达斡尔族文献数字化平台,探讨了达斡尔族文... 嫩江流域达斡尔族文献数字化建设不仅能实现其文献的永久性保存,还可以有效地开发利用文献.分析了嫩江流域达斡尔族文献保存的现状,阐述了信息时代达斡尔族文献数字化的必要性,利用TPIV7.3构建达斡尔族文献数字化平台,探讨了达斡尔族文献整理与保护的新模式,探索出促进少数民族优秀文化保护与传承的新路径. 展开更多
关键词 达斡尔族文献 tpiv7.3 数字化平台
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