Three-dimensional structure of the Lagrangian acceleration in turbulent flows
Three-dimensional structure of the Lagrangian acceleration in turbulent flows
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DOI：
10.1103/physrevlett.93.214501
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发表时间：
2004-11-19
影响因子：
8.6
通讯作者：
Bodenschatz, E
中科院分区：
文献类型：
--
作者：
Mordant, N;Crawford, AM;Bodenschatz, E
本文报道了高湍流中三维拉格朗日加速度的实验结果。示踪粒子的光学跟踪使用四个硅条探测器从高能物理，提供高的时间和空间分辨率。加速度的分量是统计相关的。加速度大小的概率密度函数类似于对数正态分布。假设各向同性，大小的对数正态分布可以解释所观察到的分量的依赖性。加速度分量的时间动力学是典型的耗散尺度，而加速度分量的大小则随时间的延长而变化，可能接近于积分时间尺度。
We report experimental results on the three-dimensional Lagrangian acceleration in highly turbulent flows. Tracer particles are tracked optically using four silicon strip detectors from high energy physics that provide high temporal and spatial resolution. The components of the acceleration are shown to be statistically dependent. The probability density function of the acceleration magnitude is comparable to a log-normal distribution. Assuming isotropy, a log-normal distribution of the magnitude can account for the observed dependency of the components. The time dynamics of the acceleration components is found to be typical of the dissipation scales, whereas the magnitude evolves over longer times, possibly close to the integral time scale.