The structure of the vorticity field in turbulent channel flow. Part 2 : Study of ensemble-averaged fields
- Author:
- Moin, P.
- Published:
- Oct 1, 1984.
- Physical Description:
- 1 electronic document
- Additional Creators:
- Kim, J.
- Access Online:
- hdl.handle.net
- Restrictions on Access:
- Unclassified, Unlimited, Publicly available.
- Summary:
- Several conditional sampling techniques are applied to a data base generated by large-eddy simulation of turbulent channel flow. It is shown that the bursting process is associated with well-organized horseshoe vortices inclined at about 45 deg. to the wall. These vortical structures are identified by examining the vortex lines of three-dimensional, ensemble averaged vorticity fields. Two distinct horseshoe-shaped vortices corresponding to the sweep and ejection events are detected. These vortices are associated with high Reynolds shear stress and hence make a significant contribution to turbulent energy production. The dependency of the ensemble averaged vortical structures on the detection criteria, and the question of whether this ensemble-averaged structure is an artifact of the ensemble averaging process are examined. The ensemble-averaged pattern of these vortical structures that emerge from the analysis could provide the basis for a hypothetical model of the organized structures of wall-bounded shear flows.
- Collection:
- NASA Technical Reports Server (NTRS) Collection.
- Note:
- Document ID: 19850004009.
Accession ID: 85N12317.
REPT-85014.
NASA-TM-86657.
NAS 1.15:86657. - Terms of Use and Reproduction:
- No Copyright.
- Access Online:
- hdl.handle.net
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