Measurements of the solid-body rotation of anisotropic particles in 3D turbulence

Guy G. Marcus, Shima Parsa, Stefan Kramel, Rui Ni, Greg A. Voth

    Research output: Contribution to journalArticlepeer-review

    55 Scopus citations


    We introduce a new method to measure Lagrangian vorticity and the rotational dynamics of anisotropic particles in a turbulent fluid flow. We use 3D printing technology to fabricate crosses (two perpendicular rods) and jacks (three mutually perpendicular rods). Time-resolved measurements of their orientation and solid-body rotation rate are obtained from four video images of their motion in a turbulent flow between oscillating grids with Rλ = 91. The advected particles have a largest dimension of 6 times the Kolmogorov length, making them a good approximation to anisotropic tracer particles. Crosses rotate like disks and jacks rotate like spheres, so these measurements, combined with previous measurements of tracer rods, allow experimental study of axisymmetric ellipsoids across the full range of aspect ratios. The measured mean square tumbling rate, 〈pi pi 〉, confirms previous direct numerical simulations that indicate that disks tumble much more rapidly than rods. Measurements of the alignment of a unit vector defining the orientation of crosses with the direction of their solid-body rotation rate vector provide the first direct observation of the alignment of anisotropic particles by the velocity gradients in a turbulent flow.

    Original languageEnglish (US)
    Article number102001
    JournalNew Journal of Physics
    StatePublished - Oct 7 2014

    All Science Journal Classification (ASJC) codes

    • General Physics and Astronomy


    Dive into the research topics of 'Measurements of the solid-body rotation of anisotropic particles in 3D turbulence'. Together they form a unique fingerprint.

    Cite this