The INI has a new website!

This is a legacy webpage. Please visit the new site to ensure you are seeing up to date information.

Skip to content



Statistics and growth rates of high-amplitude vorticity events in turbulence

Schumacher, J (TU Ilmenau)
Tuesday 30 September 2008, 14:00-14:30

Seminar Room 1, Newton Institute


Fluid turbulence is often characterized as a tangle of many intermittent vortices embedded in regions of straining motion. Although there have been many experimental and numerical studies on the evolution of isolated intense vortices, pairs of them or on the kinematics of ensembles of randomly distributed vortices, not much is known about their dynamic evolution in a fully turbulent flow. We present a high-resolution numerical simulation that monitors the formation and time evolution of high-amplitude vorticity regions. In order to identify and follow these events, we track the turbulence fields in local Cartesian frames of reference which move with Lagrangian tracers through the fluid. The local enstrophy -a measure of vorticity- shows temporal growth compatible on average with a classical prediction by Howarth and von Karman (1938). It remains well below a recently predicted rigorous upper bound for the enstrophy growth (Lu and Doering, 2008). However locally, enstrophy growth rates are detected that go beyond the mean trend and approach the predicted global bound. Related Links * - Homepage of Theoretical Fluid Mechanics Group


[pdf ]


The video for this talk should appear here if JavaScript is enabled.
If it doesn't, something may have gone wrong with our embedded player.
We'll get it fixed as soon as possible.

Back to top ∧