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Heat Transfer Variation on Protuberances and Surface Roughness ElementsIn order to determine the effect of surface irregularities on local convective heat transfer, the variation in heat transfer coefficients on small (2-6 mm diam) hemispherical roughness elements on a flat plate has been studied in a wind funnel using IR techniques. Heat transfer enhancement was observed to vary over the roughness elements with the maximum heat transfer on the upstream face. This heat transfer enhancement increased strongly with roughness size and velocity when there was a laminar boundary layer on the plate. For a turbulent boundary layer, the heat transfer enhancement was relatively constant with velocity, but did increase with element size. When multiple roughness elements were studied, no influence of adjacent roughness elements on heat transfer was observed if the roughness separation was greater than approximately one roughness element radius. As roughness separation was reduced, less variation in heat transfer was observed on the downstream elements. Implications of the observed roughness enhanced heat transfer on ice accretion modeling are discussed.
Document ID
19980050286
Document Type
Reprint (Version printed in journal)
Authors
Henry, Robert C. (Office National d'Etudes et de Recherches Aeronautiques Paris, France)
Hansman, R. John, Jr. (Massachusetts Inst. of Tech. Cambridge, MA United States)
Breuer, Kenneth S. (Massachusetts Inst. of Tech. Cambridge, MA United States)
Date Acquired
September 6, 2013
Publication Date
January 1, 1995
Publication Information
Publication: Journal of Thermophysics and Heat Transfer
Volume: 9
Issue: 1
Subject Category
Fluid Mechanics and Heat Transfer
Report/Patent Number
AIAA Paper 94-0801
NAS 1.26:207285
NASA/CR-95-207285
Meeting Information
Aerospace Sciences Meeting(Reno, NV)
Funding Number(s)
CONTRACT_GRANT: NGL-22-0069-640
CONTRACT_GRANT: NAG3-666
CONTRACT_GRANT: FAA-92/1436/A000/DRET/DR/SR
Distribution Limits
Public
Copyright
Public Use Permitted.

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