| | |
Summary: J. Fluid Mech. (2010), vol. 646, pp. 127136. c Cambridge University Press 2010
doi:10.1017/S0022112009993296
127
On the transient nature of localized pipe
flow turbulence
MARC AVILA1
, ASHLEY P. WILLIS2
AND BJ ¨ORN HOF1
1
Max Planck Institute for Dynamics and Self-Organization, 37073 G¨ottingen, Germany
2
Laboratoire d'Hydrodynamique, ´Ecole Polytechnique, 91128 Palaiseau, France
(Received 17 July 2009; revised 3 November 2009; accepted 5 November 2009)
The onset of shear flow turbulence is characterized by turbulent patches bounded by
regions of laminar flow. At low Reynolds numbers localized turbulence relaminarizes,
raising the question of whether it is transient in nature or becomes sustained at a
critical threshold. We present extensive numerical simulations and a detailed statistical
analysis of the lifetime data, in order to shed light on the sources of the discrepancies
present in the literature. The results are in excellent quantitative agreement with
recent experiments and show that turbulent lifetimes increase super-exponentially
|