Dispersion in the large-deviation regime. Part 1: shear flows and periodic flows

Large deviation rule for Anosov flows

The volume contraction in dissipative reversible transitive Anosov flows obeys a large deviation rule (fluctuation theorem).

Comparison of Turbulent Particle Dispersion Models in Turbulent Shear Flows

This work compares the performance of two Lagrangian turbulent particle dispersion models: the standard model (e.g., that presented in Sommerfeld et al. (1993)), in which the fluctuating fluid velocity experienced by the particle is composed of two components, one correlated with the previous time step and a second one randomly sampled from a Wiener process, and the model proposed by Minier and...

Geometry of turbulence in wall-bounded shear flows: periodic orbits

The dynamical theory of moderate Reynolds number turbulence triangulates the infinite-dimensional Navier-Stokes state space by sets of exact solutions (equilibria, relative equilibria, periodic orbits, ...) which form a rigid backbone which enables us to describe and predict the sinuous motions of a turbulent fluid. We report determination of a set of unstable periodic orbits from close recurre...

Reaction-Diffusion Front Speeds in Spatially-Temporally Periodic Shear Flows

We study the asymptotics of two space dimensional reaction-diffusion front speeds through mean zero space-time periodic shears using both analytical and numerical methods. The analysis hinges on traveling fronts and their estimates based on qualitative properties such as monotonicity and a priori integral inequalities. The computation uses an explicit second order upwind finite difference metho...

Chaos in Shear Flows