The Persistence Problem in Two-Dimensional Fluid Turbulence
by
Dhrubaditya Mitra
→
Europe/Stockholm
Description
We numerically study the persistence (probability distribution of
lifetime) of vortical and extensional points in incompressible
Navier--Stokes equation in two dimensions. The topological
Okubo-Weiss parameter is used to differentiate between vortical and
extensional points. In Eulerian frame the persistence probability
distribution function (PDF) shows exponential tail, but the
probability distribution of lifetime of Lagrangian particles in
vortical region shows power law tail with an universal exponent
$\theta=3.1\pm0.2$.