Chevillard L, Roux S G, Lévêque E, Mordant N, Pinton J-F, Arnéodo A
Laboratoire de Physique, CNRS & Ecole Normale Supérieure de Lyon, 46 allée d'Italie, F-69007 Lyon, France.
Phys Rev Lett. 2005 Aug 5;95(6):064501. doi: 10.1103/PhysRevLett.95.064501.
We analyze the statistics of turbulent velocity fluctuations in the time domain. Three cases are computed numerically and compared: (i) the time traces of Lagrangian fluid particles in a (3D) turbulent flow (referred to as the dynamic case); (ii) the time evolution of tracers advected by a frozen turbulent field (the static case); (iii) the evolution in time of the velocity recorded at a fixed location in an evolving Eulerian velocity field, as it would be measured by a local probe (referred to as the virtual probe case). We observe that the static case and the virtual probe cases share many properties with Eulerian velocity statistics. The dynamic (Lagrangian) case is clearly different; it bears the signature of the global dynamics of the flow.
我们在时域中分析湍流速度波动的统计数据。对三种情况进行了数值计算和比较：(i) 三维湍流中拉格朗日流体粒子的时间轨迹（称为动态情况）；(ii) 由冻结湍流场平流的示踪剂的时间演化（静态情况）；(iii) 在不断演化的欧拉速度场中固定位置记录的速度随时间的演化，就像由局部探头测量的那样（称为虚拟探头情况）。我们观察到，静态情况和虚拟探头情况与欧拉速度统计有许多共同特性。动态（拉格朗日）情况明显不同；它带有流动全局动力学的特征。
