Scaling laws and vortex profiles in twodimensional decaying turbulence
Abstract
We use high resolution numerical simulations over several hundred of turnover times to study the influence of small scale dissipation onto vortex statistics in 2D decaying turbulence. A scaling regime is detected when the scaling laws are expressed in units of mean vorticity and integral scale, like predicted in Carnevale et al., Phys. Rev. Lett. 66, 2735 (1991), and it is observed that viscous effects spoil this scaling regime. The exponent controlling the decay of the number of vortices shows some trends toward ξ=1, in agreement with a recent theory based on the Kirchhoff model [C. Sire and P. H. Chavanis, Phys. Rev. E 61, 6644 (2000)]. In terms of scaled variables, the vortices have a similar profile with a functional form related to the FermiDirac distribution.
 Publication:

Physical Review E
 Pub Date:
 June 2001
 DOI:
 10.1103/PhysRevE.63.065301
 arXiv:
 arXiv:condmat/0005468
 Bibcode:
 2001PhRvE..63f5301L
 Keywords:

 47.27.Gs;
 02.50.r;
 47.27.Jv;
 Isotropic turbulence;
 homogeneous turbulence;
 Probability theory stochastic processes and statistics;
 HighReynoldsnumber turbulence;
 Condensed Matter  Statistical Mechanics
 EPrint:
 4 Latex pages and 4 figures. Submitted to Phys. Rev. Lett