Turbulence structure and transport mechanism at the free surface in an open channel flow
Turbulence structure and transport mechanism at the free surface in an open channel flow
复制标题
明渠流自由表面的湍流结构和输运机制
DOI：
10.1016/0017-9310(82)90054-0
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发表时间：
1982
影响因子：
5.2
通讯作者：
Mizushina Tokuro
中科院分区：
文献类型：
--
作者：
Komori Satoru;Ueda Hiromasa;Ogino Fumimaru;Mizushina Tokuro
研究了明渠水流中非常接近自由面的温度场和速度场。用带IR的温度计测量了自由表面及其附近的瞬时温度。扫描仪和电阻温度计。同时用激光多普勒测速仪测量血流速度的波动。结果表明，在自由面附近，垂向运动被抑制，而流向和跨向运动被促进。表面由湍流涡流更新，其大小接近整体长度尺度，负责通过自由表面的热量和质量传递。提出了一个简单的基于这些湍流测量的表面更新模型，液侧传质系数的预测与以往气体在水洞、搅拌容器和斜板流动中的吸收数据符合得很好。
The temperature and velocity fields very close to the free surface in an open channel flow were investigated. Instantaneous temperatures at and near the free surface were measured by a thermometer with an i.r. scanner and a resistance thermometer, respectively. Velocity fluctuation was simultaneously measured by laser Doppler velocimetry. The results show that near the free surface, the vertical motions are damped, while the streamwise and span wise motions are promoted. The surface is renewed by turbulent eddies with a size close to the integral length scale, which are responsible to heat and mass transfer across the free surface. A simple surface renewal model based on these turbulence measurements was presented and the predictions of the liquid-side mass transfer coefficient showed good agreement with previous absorption data of gases into water tunnel, stirred vessel and inclined plate flows.