Call number:
ZSP-202-37
In:
Research report / Cold Regions Research and Engineering Laboratory, 37
Description / Table of Contents:
Summary: Laboratory experiments on the air permeability of various screened and natural snows are described, and, results are analyzed to determine whether the parameters obtained from the measurements could be used to define a snow type. The permeability of a snow sample of known porosity (calculated from density) was determined over a wide range of air velocities; the sample was then compacted artificially a few mm, its density was determined, and its permeability measured again. The procedure was used to obtain curves for several densities of the same sample. Air flow appeared laminar for velocities less than 5 cm/sec in fine-grained snow (less than 0.8 mm in diam.), 2 cm/sec in medium-grained snow (0.8-1.2 mm diam.), and 1 cm/sec in larger-grained snow. A formula is presented expressing all of the results obtained under laminar-flow conditions in a single relationship, and an equation for estimating grain size from initial permeability and initial porosity is suggested. Snow conversion tables and a discussion of the effect of varying sample porosity on its permeability are appended.
Type of Medium:
Series available for loan
Pages:
iv, 19, A2, B6 Seiten
,
Illustrationen
Series Statement:
Research report / Cold Regions Research and Engineering Laboratory 37
URL:
https://hdl.handle.net/11681/2710
Language:
English
Note:
CONTENTS
Page
Preface
Summary
Introduction
Apparatus and method
Experimental results and discussion
Historical background
Range of Darcy's law
Effect of porosity on the permeability of snow
Bader's equation
Conclusion
References
Appendix I. Snow conversion table: Density to absolute porosity
Appendix II. Effect on permeability of varying porosity in the sample
Porosity varies with length
Porosity varies with cross section
Location:
AWI Archive
Branch Library:
AWI Library
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