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An experimental and theoretical study of the ice accretion process during artificial and natural icing conditionsReal-time measurements of ice growth during artificial and natural icing conditions were conducted using an ultrasonic pulse-echo technique. This technique allows ice thickness to be measured with an accuracy of + or - 0.5 mm; in addition, the ultrasonic signal characteristics may be used to detect the presence of liquid on the ice surface and hence discern wet and dry ice growth behavior. Ice growth was measured on the stagnation line of a cylinder exposed to artificial icing conditions in the NASA Lewis Icing Research Tunnel (IRT), and similarly for a cylinder exposed in flight to natural icing conditions. Ice thickness was observed to increase approximately linearly with exposure time during the initial icing period. The ice accretion rate was found to vary with cloud temperature during wet ice growth, and liquid runback from the stagnation region was inferred. A steady-state energy balance model for the icing surface was used to compare heat transfer characteristics for IRT and natural icing conditions. Ultrasonic measurements of wet and dry ice growth observed in the IRT and in flight were compared with icing regimes predicted by a series of heat transfer coefficients. The heat transfer magnitude was generally inferred to be higher for the IRT than for the natural icing conditions encountered in flight. An apparent variation in the heat transfer magnitude was also observed for flights conducted through different natural icing-cloud formations.
Document ID
19880011759
Acquisition Source
Legacy CDMS
Document Type
Contractor Report (CR)
Authors
Kirby, Mark S.
(Massachusetts Inst. of Tech. Cambridge, MA, United States)
Hansman, R. John
(Massachusetts Inst. of Tech. Cambridge, MA, United States)
Date Acquired
September 5, 2013
Publication Date
April 1, 1988
Subject Category
Air Transportation And Safety
Report/Patent Number
NASA-CR-182119
DOT/FAA/CT-87/17
NAS 1.26:182119
Report Number: NASA-CR-182119
Report Number: DOT/FAA/CT-87/17
Report Number: NAS 1.26:182119
Accession Number
88N21143
Funding Number(s)
CONTRACT_GRANT: NGL-22-009-640
CONTRACT_GRANT: NAG3-666
PROJECT: RTOP 505-68-11
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
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