A coalescence model for freely decaying two-dimensional turbulence
Laboratoire de Physique (URA 1325 du CNRS), Ecole Normale Supérieure de Lyon, 69364 Lyon Cedex 07, France
Accepted: 13 July 1998
We propose a ballistic coalescence model (punctuated-Hamiltonian approach) mimicking the fusion of vortices in freely decaying two-dimensional turbulence. A temporal scaling behaviour is reached where the vortex density evolves like . A mean-field analytical argument yielding the approximation is shown to slightly overestimate the decay exponent ξ whereas Molecular Dynamics simulations give , in agreement with recent laboratory experiments and simulations of Navier-Stokes equation.
PACS: 47.27.Eq – Turbulence simulation and modeling / 05.70.Ln – Nonequilibrium thermodynamics, irreversible processes / 02.70.Ns – Molecular dynamics and particle methods
© EDP Sciences, 1998