Eliminating turbulence in spatially intermittent flows Journal Article

Author(s): Hof, Björn; de Lózar, Alberto; Avila, Marc; Tu, Xiaoyun; Schneider, Tobias M
Article Title: Eliminating turbulence in spatially intermittent flows
Abstract: Flows through pipes and channels are the most common means to transport fluids in practical applications and equally occur in numerous natural systems. In general, the transfer of fluids is energetically far more efficient if the motion is smooth and laminar because the friction losses are lower. However, even at moderate velocities pipe and channel flows are sensitive to minute disturbances, and in practice most flows are turbulent. Investigating the motion and spatial distribution of vortices, we uncovered an amplification mechanism that constantly feeds energy from the mean shear into turbulent eddies. At intermediate flow rates, a simple control mechanism suffices to intercept this energy transfer by reducing inflection points in the velocity profile. When activated, an immediate collapse of turbulence is observed, and the flow relaminarizes.
Keywords: fluid dynamics; velocity profile; channel flow; flow modeling; flow velocity; interception; laminar flow; spatial distribution; vorticity
Journal Title: Science
Volume: 327
Issue 5972
ISSN: 0036-8075
Publisher: American Association for the Advancement of Science  
Date Published: 2010-03-19
Start Page: 1491
End Page: 1494
DOI: 10.1126/science.1186091
Open access: no