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Critical transport parameters for porous media subjected to counterflowExperimental and theoretical studies have been conducted to determine critical parameters at the onset of nonlinear counterflow in He II below the lambda point of He-4. Critical temperature differences have been measured in porous media for zero net mass flow and for Darcy permeabilities in the order of magnitude range from 10 to the -10th to 10 to the -8th sq cm. The normalized critical temperature gradients, which covered the liquid temperature range of 1.5 K to the lambda temperature, are found to vary with T proportional to the ratio of the superfluid density to the normal fluid density. This liquid temperature dependence appears to be consistent with duct data which are limited at low temperature by a Reynolds number criterion.
Document ID
19910043906
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
Authors
Frederking, T. H. K.
(California Univ. Los Angeles, CA, United States)
Afifi, F. A.
(California Univ. Los Angeles, CA, United States)
Ono, D. Y.
(California, University Los Angeles, United States)
Date Acquired
August 14, 2013
Publication Date
May 1, 1989
Publication Information
Publication: Cryogenics
Volume: 29
ISSN: 0011-2275
Subject Category
Fluid Mechanics And Heat Transfer
Accession Number
91A28529
Distribution Limits
Public
Copyright
Other

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