Tracking the dynamics of translation and absolute orientation of a sphere in a turbulent flow

Robert Zimmermann (1) , Yoann Gasteuil (1) , Mickaël Bourgoin (2) , Romain Volk (1) , Alain Pumir (1) , Jean-François Pinton (1)

1 Phys-ENS - Laboratoire de Physique de l'ENS Lyon
2 LEGI - Laboratoire des Écoulements Géophysiques et Industriels [Grenoble]

We study the six-dimensional dynamics-position and orientation-of a large sphere advected by a turbulent flow. The movement of the sphere is recorded with two high-speed cameras. Its orientation is tracked using a novel, efficient algorithm; it is based on the identification of possible orientation "candidates" at each time step, with the dynamics later obtained from maximization of a likelihood function. Analysis of the resulting linear and angular velocities and accelerations reveal a surprising intermittency for an object whose size lies in the inertial range, close to the integral scale of the underlying turbulent flow.

Domaines: Mécanique des fluides [physics.class-ph]; Mécanique des fluides [physics.class-ph]

Robert Zimmermann, Yoann Gasteuil, Mickaël Bourgoin, Romain Volk, Alain Pumir, et al.. Tracking the dynamics of translation and absolute orientation of a sphere in a turbulent flow. Review of Scientific Instruments, 2011, 82, pp.033906. ⟨10.1063/1.3554304⟩. ⟨hal-00941495⟩