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Convective heat transfer from circular cylinders located within perforated cylindrical shroudsThe influence of perforated cylindrical shrouds on the convective heat transfer to circular cylinders in transverse flow has been studied experimentally. Geometries studied were similar to those used in industrial platinum resistance thermometers. The influence of Reynolds number, ventilation factor (ratio of the open area to the total surface area of shroud), radius ratio (ratio of shroud's inside radius to bare cylinder's radius), and shroud orientation with respect to flow were studied. The experiments showed that perforated shrouds with ventilation factors in the range 0.1 to 0.4 and radius ratios in the range 1.1 to 2.1 could enhance the convective heat transfer to bare cylinders up to 50%. The maximum enhancement occurred for a radius ratio of 1.4 and ventilation factors between 0.2 and 0.3. It was found that shroud orientation influenced the heat transfer, with maximum heat transfer generally occurring when the shroud's holes were centered on either side of the stagnation line. However, the hole orientation effect is of second order compared to the influence of ventilation factor and radius ratio.
Document ID
19860020628
Acquisition Source
Legacy CDMS
Document Type
Contractor Report (CR)
Authors
Daryabeigi, K.
(Old Dominion Univ. Norfolk, VA, United States)
Ash, R. L.
(Old Dominion Univ. Norfolk, VA, United States)
Date Acquired
September 5, 2013
Publication Date
August 1, 1986
Publication Information
Publisher: NASA
Subject Category
Fluid Mechanics And Heat Transfer
Report/Patent Number
NAS 1.26:4005
NASA-CR-4005
Accession Number
86N30100
Funding Number(s)
CONTRACT_GRANT: NAS1-17993
PROJECT: RTOP 505-61-01-05
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
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