Qureshi Nauman M, Bourgoin Mickaël, Baudet Christophe, Cartellier Alain, Gagne Yves
Laboratoire des Ecoulements Géophysiques et Industriels, CNRS/UJF/INPG UMR5519, BP53, 38041 Grenoble, France.
Phys Rev Lett. 2007 Nov 2;99(18):184502. doi: 10.1103/PhysRevLett.99.184502. Epub 2007 Oct 31.
We present experimental Lagrangian statistics of finite sized, neutrally bouyant, particles transported in an isotropic turbulent flow. The particle's diameter is varied over turbulent inertial scales. Finite size effects are shown not to be trivially related to velocity intermittency. The global shape of the particle's acceleration probability density functions is not found to depend significantly on its size while the particle's acceleration variance decreases as it becomes larger in quantitative agreement with the classical k(-7/3) scaling for the spectrum of Eulerian pressure fluctuations in the carrier flow.
我们给出了在各向同性湍流中传输的有限尺寸、中性浮力粒子的实验拉格朗日统计量。粒子直径在湍流惯性尺度范围内变化。结果表明,有限尺寸效应与速度间歇性并非简单相关。未发现粒子加速度概率密度函数的整体形状显著依赖于其尺寸,而粒子加速度方差随着其尺寸增大而减小,这与载流中欧拉压力波动谱的经典k^(-7/3)标度在定量上一致。