Lagrangian chaos and turbulence in fluid dynamics

Abstract

Randomization of the Lagrangian chaos in fluid dynamics has been analyzed using results of direct numerical simulations, laboratory measurements, and oceanic observations. The notion of distributed chaos has been used in order to quantify this phenomenon (the main dimensionless parameter of distributed chaos has been used as a measure of randomization). The analysis includes isotropic homogeneous fluid motion, buoyancy-driven flows, particle-laden flows, magnetohydrodynamic flows, and subsurface oceanic mixing. The role of the dissipative Birkhoff-Saffman and Loitsyanskii invariants as well as the invariants related to the spontaneous breaking of the local reflectional symmetry (in particular, the Levich-Tsinober invariant) in the randomization phenomenon has been also investigated.