SAMPLING OF INTERNAL WAVES AND NATURAL CONVECTION IN A RESERVOIR BASED ON WATER TEMPERATURE MEASUREMENTS
SAMPLING OF INTERNAL WAVES AND NATURAL CONVECTION IN A RESERVOIR BASED ON WATER TEMPERATURE MEASUREMENTS
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基于水温测量的水库内波和自然对流采样
DOI：
10.2208/prohe.43.1049
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发表时间：
1999
期刊：
影响因子：
--
通讯作者：
Katsuhisa Ishikawa
中科院分区：
文献类型：
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作者：
K. Michioku;T. Kanda;Katsuhisa Ishikawa
使用三十通道热敏电阻链在垂直多点同时测量水库水温。每 10.5 秒收集一次数据，以便检测更短时间尺度的运动。目的是对内波和自然对流运动进行研究，这些运动对湍流能量传递和水质量输送有很大影响。通过过滤水温时间序列和互相关分析来检查内波传播。时空坐标系中的传播图成功地描述了内波的尺度、模式和传播特性。通过分析冬夜收集的数据集来研究自然对流。应用条件采样 VITA（变分间隔时间平均）来检测由于夜间冷却而产生的有组织的运动。从温度的条件平均时间序列中，得到了自然对流的速度尺度，它与迪尔多夫速度尺度非常吻合。评估了夹带率和垂直湍流热通量，这与小规模实验模型中发现的结果有很好的相关性。
Reservoir water temperature was measured simultaneously at vertical multi-points using a thirty-channel thermistor chain. Data were collected every 10.5-second in order to detect even short time-scale motions. The objective is to make investigation on internal waves and natural convective motions that are much responsible for turbulent energy transfer as well as for water mass transport. Internal wave propagation was examined by filtering time series of water temperature and a cross-correlation analysis. A propagation diagram in a spacetime coordinate system successfully described scales, modes and propagation characteristics of internal waves. Natural convection was investigated by analyzing dataset collected during winter nights. A conditional sampling, VITA-Variational Interval Time Averaging-was applied to detect organized motions due to nocturnal cooling. From conditionally averaged time series of temperature, a velocity scale of natural convection was obtained, which well agreed with the Deardorff's velocity scale. Entrainment rate and vertical turbulent heat flux were evaluated, which were well correlated to those found in small-scale experimental models.