Editor's Summary
7 September 2006
Turbulence times
Most flows in nature are turbulent, such as flows in the atmosphere, the oceans, in the cores of planets and around vehicles. The commonly accepted view is that if a (steadily driven) flow becomes turbulent, it stays in this state indefinitely. New work on a system with many parallels in nature, a fluid flowing through straight pipes and channels, has come up with a surprise result: turbulence decays after a finite time. Though finite, the lifetime increases rapidly with flow rate, and even at moderate speeds can reach unobservably long timescales. Nevertheless, this discovery could be exploited to control turbulent flows.
News and Views: Fluid dynamics: Turbulence lost in transience
Turbulence is generally regarded as a permanent feature of many fluid flows. That assumption is challenged by the claim that shear turbulence has a limited lifetime — albeit sometimes a very long one.
Daniel Perry Lathrop
doi:10.1038/443036a
Letter: Finite lifetime of turbulence in shear flows
Björn Hof, Jerry Westerweel, Tobias M. Schneider and Bruno Eckhardt
doi:10.1038/nature05089
First paragraph | Full Text | PDF (211K) | Supplementary information
