| Issue |
J. Phys. I France
Volume 4, Number 8, August 1994
|
|
|---|---|---|
| Page(s) | 1115 - 1120 | |
| DOI | https://doi.org/10.1051/jp1:1994241 | |
J. Phys. I France 4 (1994) 1115-1120
Short Communication
Free and layer turbulent percolation: topological instabilities and their suppression
A. Bershadskii1 and H. Branover21 P.O.Box 39953, Ramat-Aviv 61398, Tel-Aviv, Israel
2 Center for MHD-Studies, Ben-Gurion University, Beer-Sheva, Israel
(Received 25 April 1994, revised 26 May 1994, accepted 7 June 1994)
Abstract
It is shown (theoretically and experimentally) that topological instabilities lead to free
percolation of passive scalar in quasi two-dimensional turbulence that is characterized by
the these-dimensional value of the critical exponent
and by spectral exponent
"
-4/3". Suppression of these instabilities transforms the percolation to layer-type process
with
and spectral exponent "-7/3". In the last case fractal dimension of the
passive scalar cluster equals 9/4 and fractal dimension of its perimeter equals 7/4 (i.e. is
the same as fractal dimension of the hull of strictly two-dimensional percolation cluster). A
good correspondence is found between the spectral and the fractal scaling laws and the
atmospheric, numerical and laboratory experimental data.
© Les Editions de Physique 1994