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Aerodynamic levitation of laser-heated solids in gas jetsThe aerodynamic levitation technique is developed for studies of high-temperature material properties and gas/condensed-phase reaction kinetics. Stable levitation is demonstrated in a supersonic jet from a 0.081 cm nozzle with 0.03-0.20 g 0.24-0.47 cm diameter solid spheres at a height between 0.7-2.0 cm above the nozzle and ambient pressures between 1.1-18 Torr. A model of supersonic jet levitation is developed which accurately predicts the values of height vs pressure over the full range of conditions investigated. It is found that the efficiency with which jet momentum is converted into levitation force decreases with the jet/specimen diameter ratio and the jet Reynolds number, and the rate of jet spreading with distance from the nozzle is found to agree with that measured by pitot tube traverses of the jet. In addition, laser heating is shown to reduce the jet momentum required for levitation at a given height and to increase levitation stability. Measurements of sphere levitation in subsonic gas jets show that the required jet momentum flow rate exceeds the specimen weight by about 2/the specimen drag coefficient at its terminal free-fall speed under ambient conditions.
Document ID
19820062888
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Nordine, P. C.
(Yale Univ. New Haven, CT, United States)
Atkins, R. M.
(Yale University New Haven, CT, United States)
Date Acquired
August 10, 2013
Publication Date
September 1, 1982
Publication Information
Publication: Review of Scientific Instruments
Volume: 53
Subject Category
Instrumentation And Photography
Accession Number
82A46423
Funding Number(s)
CONTRACT_GRANT: ARPA ORDER 3438
Distribution Limits
Public
Copyright
Other

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