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Radiation and phase change of lithium fluoride in an annulusA one-dimensional thermal model is developed to evaluate the effect of radiation on the phase change of lithium-fluoride (LiF) in an annular canister under gravitational and microgravitational conditions. Specified heat flux at the outer wall of the canister models focused solar flux; adiabatic and convective conditions are considered for the inner wall. A two-band radiation model is used for the combined-mode heat transfer within the canister, and LiF optical properties relate metal surface properties in vacuum to those in LiF. For axial gravitational conditions, the liquid LiF remains in contact with the two bounding walls, whereas a void gap is used at the outer wall to model possible microgravitational conditions. For the adiabatic cases, exact integrals are obtained for the time required for complete melting of the LiF. Melting was found to occur primarily from the outer wall in the 1-g model, whereas it occurred primarily from the inner wall in the mu-g model. For the convective cases, partially melted steady-state conditions and fully melted conditions are determined to depend on the source flux level, with radiation extending the melting times.
Document ID
19930070463
Document Type
Reprint (Version printed in journal)
Authors
Lund, Kurt O. (California Univ. La Jolla, United States)
Date Acquired
August 16, 2013
Publication Date
December 1, 1993
Publication Information
Publication: Journal of Thermophysics and Heat Transfer
Volume: 7
Issue: 4
ISSN: 0887-8722
Subject Category
MATERIALS PROCESSING
Funding Number(s)
CONTRACT_GRANT: NAG3-1106
Distribution Limits
Public
Copyright
Other