Measurement of Turbulent Kinetic Energy Dissipation Rate with a Lagrangian Float
Measurement of Turbulent Kinetic Energy Dissipation Rate with a Lagrangian Float
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DOI：
10.1175/jtech1890.1
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发表时间：
2006-07
影响因子：
2.2
通讯作者：
R. Lien;E. D’Asaro
中科院分区：
文献类型：
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作者：
R. Lien;E. D’Asaro
本文用惯性子极差法测试了中性浮体从垂直加速度谱估算湍流动能耗散率e的能力。拉格朗日浮子配备了Sontek声学多普勒测速仪(ADV)和压力传感器，前者测量浮子中心下方1米处的矢量速度，后者测量浮子的深度。测量是在估计e从10−8到10−3 W kg−1的流动中进行的。以前的观测和理论研究得出结论，拉格朗日加速度谱在惯性子范围内是白色的，水平与e成正比。拉格朗日浮子的大小在高频下引入了高度可重复性的谱衰减。通过将观测到的谱与包含衰减效应的模型谱进行拟合，得到了使用浮子测量的湍流动能耗散率的估计值。将ADV速度测量换算成…
Abstract This study tests the ability of a neutrally buoyant float to estimate the dissipation rate of turbulent kinetic energy e from its vertical acceleration spectrum using an inertial subrange method. A Lagrangian float was equipped with a SonTek acoustic Doppler velocimeter (ADV), which measured the vector velocity 1 m below the float's center, and a pressure sensor, which measured the float's depth. Measurements were taken in flows where estimates of e varied from 10−8 to 10−3 W kg−1. Previous observational and theoretical studies conclude that the Lagrangian acceleration spectrum is white within the inertial subrange with a level proportional to e. The size of the Lagrangian float introduces a highly reproducible spectral attenuation at high frequencies. Estimates of the dissipation rate of turbulent kinetic energy using float measurements efloat were obtained by fitting the observed spectra to a model spectrum that included the attenuation effect. The ADV velocity measurements were converted to a ...