Characterization of a large vortex using acoustic time-reversal mirrors
Laboratoire Ondes et Acoustique (URA CNRS 1503) , ESPCI, Université Paris VII,
10 rue Vauquelin, 75005 Paris, France
2 Laboratoire de Physique et Mécanique des Milieux Hétérogènes (URA CNRS 857) , ESPCI, 10 rue Vauquelin, 75005 Paris, France
Published online: 15 June 1999
We report new results on the ultrasonic characterization of a fluid flow using an acoustic time-reversal mirror (TRM). The structure of a large vortex generated by a rotating disk in a hollow cylinder is investigated both inside and below the cylinder. For mean-flow characterization, the TRM is shown to be a powerful vorticity detector. Experimental time-of-flight data are successfully compared to a numerical simulation of the flow and the orthoradial velocity is reconstructed using simple geometrical acoustics. Real-time measurements allow us to extract the precession motion of the vortex, providing direct, non-intrusive, and dynamical information on the flow.
PACS: 43.30+m – Underwater sound / 43.35+d – Ultrasonics, quantum acoustics, and physical effects of sound / 47.32-y – Rotational flow and vorticity
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 1999