4 research outputs found
On the decay of turbulence in plane Couette flow
The decay of turbulent and laminar oblique bands in the lower transitional
range of plane Couette flow is studied by means of direct numerical simulations
of the Navier--Stokes equations. We consider systems that are extended enough
for several bands to exist, thanks to mild wall-normal under-resolution
considered as a consistent and well-validated modelling strategy. We point out
a two-stage process involving the rupture of a band followed by a slow
regression of the fragments left. Previous approaches to turbulence decay in
wall-bounded flows making use of the chaotic transient paradigm are
reinterpreted within a spatiotemporal perspective in terms of large deviations
of an underlying stochastic process.Comment: ETC13 Conference Proceedings, 6 pages, 5 figure