Space-time correlation structures of horizontal coherent vortices in compound open-channel flows by using particle-tracking velocimetry
作者:
Iehisa Nezu,
Tadanobu Nakayama,
期刊:
Journal of Hydraulic Research
(Taylor Available online 1997)
卷期:
Volume 35,
issue 2
页码: 191-208
ISSN:0022-1686
年代: 1997
DOI:10.1080/00221689709498426
出版商: Taylor & Francis Group
数据来源: Taylor
摘要:
In compound open-channel flows, it is very important to clarify an interaction mechanism between the mainchannel and flood-plains induced by coherent vortices, so-called the“intermittent upward secondary currents”and the“large-scale horizontal vortices”, as shown in Figure 1. In the present study, time-averaged structures of secondary currents were revealed experimentally by making use of a two-component fiber-optic Laser Doppler Anemometer (LDA). Next, a new quantitative visualization technique called the “Particle-Tracking Velocimetry (PTV)” was used to investigate evolutionary patterns of horizontal large-scale vortices, which are the ultimate interest in a shallow water flood-plain. By this technique, instantaneous velocity components in arbitrary horizontal plane were obtained at all grid points of laser-light-sheet (LLS) from continuous four images of one particle, and space-time correlation structures of coherent vortices between the main-channel and flood-plain were investigated by using a conditional sampling technique.
点击下载:
PDF (11303KB)
返 回