High order Lagrangian velocity statistics in turbulence.
High order Lagrangian velocity statistics in turbulence.
复制标题
DOI：
10.1103/physrevlett.96.024503
复制
发表时间：
2006-01
影响因子：
8.6
通讯作者：
Haitao Xu;M. Bourgoin;N. Ouellette;E. Bodenschatz
中科院分区：
文献类型：
--
作者：
Haitao Xu;M. Bourgoin;N. Ouellette;E. Bodenschatz
我们报告了高雷诺数（高达 R(lambda) = 815 的泰勒微尺度雷诺数）湍流实验中 1 至 10 阶拉格朗日速度结构函数的测量结果。被动示踪粒子在三维和时间上进行光学跟踪，并根据粒子轨迹计算速度。结构函数反常标度指数可以直接测量，也可以使用扩展自相似性进行测量，并且发现其比欧拉对应物更具间歇性。经典柯尔莫哥洛夫惯性范围标度也适用于所有结构函数阶数，有时随着阶数的增加而呈下降趋势。随着结构函数阶数的增加时间短于柯尔莫哥洛夫时间尺度，这种经典尺度行为的时间变化被观察到饱和。
We report measurements of the Lagrangian velocity structure functions of orders 1 through 10 in a high Reynolds number (Taylor microscale Reynolds numbers of up to R(lambda) = 815 ) turbulence experiment. Passive tracer particles are tracked optically in three dimensions and in time, and velocities are calculated from the particle tracks. The structure function anomalous scaling exponents are measured both directly and using extended self-similarity and are found to be more intermittent than their Eulerian counterparts. Classical Kolmogorov inertial range scaling is also found for all structure function orders at times that trend downward as the order increases. The temporal shift of this classical scaling behavior is observed to saturate as the structure function order increases at times shorter than the Kolmogorov time scale.