NASO , Aurore

This thesis is divided into two parts. In the first one is studied a model of hydrodynamic turbulence which consists of a set of stochastic differential equations. At first, one presents the solutions of this system calculated in the semiclassical approximation, then those obtained through a Monte-Carlo-type method adapted to the problem, in...

Velocity fluctuations in hydrodynamic turbulence have a nontrivial structure, characterized by correlations of the velocity gradient tensor. In this paper, we consider a phenomenological model, incorporating the main features of hydrodynamic fluid turbulence, aimed at predicting the structure of the velocity gradient tensor M coarse grained at...

International audience

A simplified thermodynamic approach of the incompressible axisymmetric Euler equations is considered based on the conservation of helicity, angular momentum and microscopic energy. Statistical equilibrium states are obtained by maximizing the Boltzmann entropy under these sole constraints. We assume that these constraints are selected by the...

We study the transition to spatiotemporal chaos in a two-dimensional hydrodynamic experiment where liquid columns take place in the gravity induced instability of a liquid film. The film is formed below a plane grid which is used as a porous media and is continuously supplied with a controlled flow rate. This system can be either ordered (on a...