# Laboratoire de Mécanique des Fluides et d’Acoustique - UMR 5509

LMFA - UMR 5509
Laboratoire de Mécanique des Fluides et d’Acoustique
Lyon
France

## Wouter Bos

Groupe de Recherche : Turbulence & Instabilités
tél : 04.72.18.62.04
email

Research in the spotlight :

### Football players and turbulent trajectories (with B. Kadoch and K. Schneider)

(...) Indeed, even though a football match does not seem to be ergodic, and some may argue that the trajectories of football players are not completely random, the long-time PDF of the directional change converged to a shape close to the one for fluid particles (...)

Recent experiments and simulations have shown that unsteady turbulent flows display a universal behavior at short and intermediate times, different from classical scaling relations. The origin of these observations is explained and the exact form of the observed universal scaling is derived. The derived scaling for the normalized dissipation rate $C_\epsilon$ as a function of the Reynolds number $R_\lambda$ is,
$$C_\epsilon\sim R_\lambda^{-15/14},$$