Exact Invariant Solutions for Coherent Turbulent Motions in Couette and Poiseuille Flows

Subhandu Rawat (1) , Carlo Cossu (1) , François Rincon (2)

1 IMFT - Institut de mécanique des fluides de Toulouse
2 IRAP - Institut de recherche en astrophysique et planétologie

The dynamical systems approach recently applied to understand subcritical transitions in wall-bounded shear flows is combined with the use of large-eddy simulations to investigate the nature of large-scale coherent motions in turbulent Couette and Poiseuille flows. Exact invariant solutions of the filtered Navier-Stokes (LES) equations are computed by using the Smagorinsky model to parametrize small-scale motions. These solutions can be continued into exact solutions of the Navier-Stokes equations, therefore providing a bridge between coherent large-scale motions in wall-bounded fully developed turbulent flows and invariant solutions appearing in transitional flows.

Mots clés: Turbulence; Coherent structures; Dynamical systems

Domaines: Dynamique des Fluides [physics.flu-dyn]; Mécanique des fluides [physics.class-ph]

Subhandu Rawat, Carlo Cossu, François Rincon. Exact Invariant Solutions for Coherent Turbulent Motions in Couette and Poiseuille Flows. 24th International Congress of Theoretical and Applied Mechanics (ICTAM), IUTAM, Aug 2016, Montréal, Canada. pp.94-98, ⟨10.1016/j.piutam.2017.03.013⟩. ⟨hal-02869020⟩