| Issue |
J. Phys. II France
Volume 6, Number 4, April 1996
|
|
|---|---|---|
| Page(s) | 573 - 583 | |
| DOI | https://doi.org/10.1051/jp2:1996198 | |
J. Phys. II France 6 (1996) 573-583
Observation of Intense Filaments in Fully Developed Turbulence
F. Belin, J. Maurer, P. Tabeling and H. WillaimeLaboratoire de Physique Statistique, École Normale Supérieure, 24 rue Lhomond, 75231 Paris Cedex 05, France
(Received 3 May 1995, revised 10 November 1995, accepted 3 January 1996)
Abstract
We study the structure of the large events which control the tails of the pdf of the velocity
derivatives in an helium experiment. For
, we find that these events have a
remarkable structure, which is consistent with that of intense vortex filaments ("worms")
observed previously in numerical studies. The characteristics of such objects (form, size
and circulation distributions, scaling wih the Reynolds number) are in good agreement with
reported numerical findings. These objects do not contribute significantly to the overall
dissipation but they control an important part of the intermittency in the inertial range.
Above
, the structure of such events dramatically changes;
we interpret this observation as an instability. We finally offer a physical interpretation
of a previous experiment showing that around
, the flatness of the
velocity derivatives shows a transitional behaviour.
© Les Editions de Physique 1996