摘要
采用双层横向振荡格栅生成的紊流分别研究了纯淡水和不同盐度梯度层化水体的紊动特性。通过声学多普勒流速仪和设计开发的多通道微型盐度测量仪同步测量了水体紊动和盐度的历时变化过程,分别从水体紊动的均方根流速、紊动强度和紊动能谱等紊动特性的变化分析了盐度层化对水体紊动的影响。实验结果表明盐度层化会抑制水体紊动,减弱水体紊动强度,并且盐度梯度越大水体紊动抑制程度越大。定义了表征振荡格栅紊流中水体层化程度的无量纲层化参数,水体紊动抑制率随层化参数的增大而增大,拟合得到层化参数和紊动抑制率的关系式。
Turbulent flows generated by double-layer transverse oscillation grids are used to study the turbulence characteristics of pure fresh water and salt water stratified with different salinity gradients.Time variations in turbulence and salinity are measured simultaneously using an acoustic Doppler velocimeter and a multi-channel micro-salinity meter that was designed in our laboratory.This paper focuses on an analysis of the effects of salinity stratification on turbulent characteristics such as root mean square velocity,turbulence intensity,and turbulent kinetic energy spectrum.The results show that the stratification suppresses turbulences and weakens turbulence intensity,and a larger salinity gradient leads to more suppression of turbulences.A dimensionless stratification parameter is defined to represent the stratification degree of a water body under oscillating grid turbulences.Our analysis reveals the turbulence suppression rate increases as this parameter is increased,and a relationship between them is obtained through data fitting.
作者
黄睿
张庆河
邢恩博
张金凤
HUANG Rui;ZHANG Qinghe;XING Enbo;ZHANG Jinfeng(State Key Laboratory of Hydraulic Engineering Simulation and Safety,Tianjin University,Tianjin 300072)
出处
《水力发电学报》
EI
CSCD
北大核心
2020年第3期45-55,共11页
Journal of Hydroelectric Engineering
基金
国家自然科学基金项目(51679161).
关键词
盐度
层化
紊动特性
振荡格栅
微型盐度传感器
salinity
stratification
turbulence characteristic
oscillating grid
micro salinity sensor
