Del Castello Lorenzo, Clercx Herman J H
Department of Physics and J. M. Burgers Centre for Fluid Dynamics, Eindhoven University of Technology, P. O. Box 513, 5600 MB Eindhoven, The Netherlands.
Phys Rev E Stat Nonlin Soft Matter Phys. 2011 May;83(5 Pt 2):056316. doi: 10.1103/PhysRevE.83.056316. Epub 2011 May 16.
Lagrangian statistics of passive tracers in rotating turbulence is investigated by particle tracking velocimetry. A confined and steadily forced turbulent flow is subjected to five different rotation rates. The PDFs of the velocity components clearly reveal the anisotropy induced by background rotation. Although the statistical properties of the horizontal turbulent flow field are approximately isotropic, in agreement with previously reported results by van Bokhoven and coworkers [Phys. Fluids 21, 096601 (2009)], the velocity component parallel to the (vertical) rotation axis gets strongly reduced (compared to the horizontal ones) while the rotation is increased. The auto-correlation coefficients of all three components are progressively enhanced for increasing rotation rates, although the vertical one shows a tendency to decrease for slow rotation rates. The decorrelation is approximately exponential. Lagrangian data compare favorably with previously reported Eulerian data for horizontal velocity components but show a different behavior for the vertical velocity components at higher rotation rates.
