Release Time:2019-03-12  Hits:

Indexed by: Journal Article

Date of Publication: 2016-11-01

Journal: SCIENCE CHINA-PHYSICS MECHANICS & ASTRONOMY

Included Journals: Scopus、EI、SCIE

Volume: 59

Issue: 11

ISSN: 1674-7348

Key Words: optimal dynamical systems; helical-wave decomposition; fundamental elements of turbulence; vortex structures

Abstract: In this paper, we present the theory of constructing optimal generalized helical-wave coupling dynamical systems. Applying the helical-wave decomposition method to Navier-Stokes equations, we derive a pair of coupling dynamical systems based on optimal generalized helical-wave bases. Then with the method of multi-scale global optimization based on coarse graining analysis, a set of global optimal generalized helical-wave bases is obtained. Optimal generalized helical-wave bases retain the good properties of classical helical-wave bases. Moreover, they are optimal for the dynamical systems of Navier-Stokes equations, and suitable for complex physical and geometric boundary conditions. Then we find that the optimal generalized helical-wave vortexes fitted by a finite number of optimal generalized helical-wave bases can be used as the fundamental elements of turbulence, and have important significance for studying physical properties of complex flows and turbulent vortex structures in a deeper level.