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Memorias de investigación
Communications at congresses:
Temporal evolution of Townsends attached eddies
Year:2013
Research Areas
  • Turbulence
Information
Abstract
The temporal evolution of the eddies responsible for the momentum transfer in a turbulent channel are studied using time-resolved DNS data at Re?=4000. The eddies are identified as connected regions of intense tangential Reynolds stress, and tracked in time. Once their evolutions are properly organized, they provide the necessary information to characterize eddies from birth to death. Eddies are born at all distances from the wall, although with higher probability near it, where the shear is strongest. Most of them stay small and do not last for long times. However, there is a family of eddies that become large enough to get attached to the wall while they reach into the logarithmic layer. They can be considered the best candidates for Townsend's attached eddies found until now. They are geometrically self-similar, with sizes and lifetimes proportional to their distance from the wall. Eddies associated with ejections move away from the wall with dy/dt=u?, and their base attaches very fast at the beginning of their lives. Conversely, sweeps move towards the wall at ?u?, and attach later. In both cases, they remain attached for 2/3 of their lives. In the streamwise direction, eddies are advected and sheared by the local mean velocity.
International
Si
Congress
66th Annual Meeting of the Division of Fluid Dynamics of the American Physical Society
960
Place
Pittsburgh (USA)
Reviewers
Si
ISBN/ISSN
0003-0503
Start Date
24/11/2013
End Date
26/11/2013
From page
234
To page
234
Temporal evolution of Townsends attached eddies
Participants
  • Autor: Adrian Lozano Duran (UPM)
  • Autor: Javier Jimenez Sendin (UPM)
Research Group, Departaments and Institutes related
  • Creador: Grupo de Investigación: Mecánica de Fluidos Computacional
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