NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
An experimental study of changes in the structure of a turbulent boundary layer due to surface geometry changesThis investigation attempts to observe changes in the flow structure of a nominally zero pressure gradient turbulent boundary layer by altering the surface of a smooth plate with small triangular riblets oriented in the direction of flow and protruding just above the viscous sublayer. Hot-wire measurements show a reduction in the local skin friction over the riblet valleys by about 40% compared to the smooth surface near the end of the plate. Local skin friction increases by about 10% over the riblet peaks. Results showing the effects of the riblets on the mean, root-mean-square and skewness factor distributions of the streamwise velocity are presented. The mean profile displays characteristics similar to those of drag reducing additives; the streamwise turbulence intensity is reduced by approximately 10-15% near the surface by the riblets; the skewness factor distribution is virtually unchanged. A comparison of results from an application of the VITA 'burst' detection technique to smooth and riblet surface data is also presented although the results are rather inconclusive. Flow visualization of 'bursting' over both surfaces, while dramatically revealing the structure, reveals little difference resulting from the presence of the riblet.
Document ID
19830035381
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Date Acquired
August 11, 2013
Publication Date
January 1, 1983
Subject Category
Fluid Mechanics And Heat Transfer
Report/Patent Number
AIAA PAPER 83-0230
Meeting Information
Meeting: American Institute of Aeronautics and Astronautics, Aerospace Sciences Meeting
Location: Reno, NV
Start Date: January 10, 1983
End Date: January 13, 1983
Accession Number
83A16599
Funding Number(s)
CONTRACT_GRANT: NAG1-24
Distribution Limits
Public
Copyright
Other

Available Downloads

There are no available downloads for this record.
No Preview Available