title: Tracking the dynamics of translation and absolute orientation of a sphere in a turbulent flow.
abstract: 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.
authors: Laboratoire de Physique, CNR, UMR 5672, Ecole Normale Supérieure de Lyon, Lyon F-69007, France.
authors: Robert
authors: R
authors: Zimmermann
authors: Yoann
authors: Y
authors: Gasteuil
authors: Mickael
authors: M
authors: Bourgoin
authors: Romain
authors: R
authors: Volk
authors: Alain
authors: A
authors: Pumir
authors: Jean-François
authors: JF
authors: Pinton