Statistical scale of hairpin packets in the later stage of bypass transition induced by cylinder wake
Statistical scale of hairpin packets in the later stage of bypass transition induced by cylinder wake
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气缸尾流引起的旁路过渡后期发夹包统计规模
DOI：
10.1007/s00348-012-1291-7
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发表时间：
2012-03
期刊：
影响因子：
--
通讯作者：
Jiang N
中科院分区：
文献类型：
--
作者：
Tang ZQ;Jiang N
利用时间分辨粒子图像测速技术分别从侧面和顶部观察了圆柱尾迹诱导的绕流转捩后期发夹包的结构及其统计尺度。线性随机估计被用来获得条件平均速度场。对于侧视情况，有条件平均结构由一系列沿沿着与壁面成大角度（18°）倾斜的直线的旋涡运动和在它们正上方出现的圆柱尾迹所占据的低速区组成。在壁面法向高度/δ = 0.2的（x，z）平面上，主要结构是沿流向沿着约3δ长的大尺度低动量区。低速区始终以小尺度反向旋转涡对为边界，这些涡对沿流向组织，统计展向宽度为0.55δ。结果表明，在过渡区的后期，圆柱尾迹的向上诱导增强了发夹包的壁面法向和展向范围。
The hairpin packet's structure and its statistical scale in the later stage of bypass transition induced by a cylinder wake are investigated by time-resolved particle image velocimetry from the side and top view, respectively. Linear stochastic estimation is used to achieve the conditionally averaged velocity fields. For the side view case, the conditionally averaged structure consists of a series of swirling motions located along a line inclining at a large angle (18°) from the wall and a low-speed region occupied by the cylinder wake appearing right above them. In the (x,z)-plane at the wall-normal heighty/δ = 0.2, the dominant structures are shown to be the large-scale regions of low momentum elongated almost over 3δ along the streamwise. The low-speed regions are consistently bordered by small-scale counter-rotating vortice pairs organized in the streamwise with a statistical spanwise width of 0.55δ. The results suggest that in the later part of the transitional zone, the upward induction of the cylinder wake enhances both the wall-normal and spanwise extent of the hairpin packets.
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DOI：
10.1007/978-3-642-83787-6_4
发表时间：
1989
期刊：
--
影响因子：
--
作者：
L. Lourenço
通讯作者：
L. Lourenço
气缸尾流引起的旁路过渡中的相干结构
影响因子：
3.7
作者：
Feng, Li Hao;Pan, Chong;Wang, Jin Jun;Zhang, Pan Feng
通讯作者：
Zhang, Pan Feng
影响因子：
2.4
作者：
Christensen, KT
通讯作者：
Christensen, KT
DOI：
10.1007/978-1-4899-5579-1_1
发表时间：
1969
期刊：
--
影响因子：
--
作者：
M. Morkovin
通讯作者：
M. Morkovin
DOI：
10.1007/978-3-7091-2676-9_3
发表时间：
1996
期刊：
--
影响因子：
--
作者：
R. Adrian
通讯作者：
R. Adrian