Topologies of Shear and Strain Promote Chaotic Mixing in Helical Flow

EasyChair Preprint 8437

Abstract

Physics aids explainable artificial intelligence. The inherent topology of a chaotic system is often a boon to learning algorithms. Helical or screw flows are chaotic. Their velocity and rotational fields are parallel to each other, typically hosting coherent structures that contain (either strain or shear) barriers which resist fluid flow across them. Here, we apply perturbation to coherent fluid particles to construct a criterion governing the topological changes in their mixing across barriers, which we define using the macroscopic statistical measure of finite-time Lyapunov exponent. Our findings demonstrate that the rigid coherent structures essentially support mixing in purely helical flows. These findings have far-reaching implications in diverse fields of applications, ranging from dynamos in growing magnetic field, classical turbulence in superfluid helium to supercell atmospheric tornadoes.

Keyphrases: Chaos, Helicity, Lyapunov exponent, streamline

@booklet{EasyChair:8437,
  author    = {Priyam Chakraborty},
  title     = {Topologies of Shear and Strain Promote Chaotic Mixing in Helical Flow},
  howpublished = {EasyChair Preprint 8437},
  year      = {EasyChair, 2022}}