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A note on momentum transfer above very rough surfaces
Author(s) -
Mulhearn P. J.
Publication year - 1979
Publication title -
quarterly journal of the royal meteorological society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.744
H-Index - 143
eISSN - 1477-870X
pISSN - 0035-9009
DOI - 10.1002/qj.49710544515
Subject(s) - wind tunnel , surface finish , momentum transfer , porosity , field (mathematics) , momentum (technical analysis) , mechanics , meteorology , surface roughness , physics , geometry , geology , mathematics , materials science , optics , geotechnical engineering , thermodynamics , composite material , pure mathematics , finance , scattering , economics
Data from wind tunnel experiments on the deviations from unity of the non‐dimensional velocity gradient, Φ M = (kz/u * )(δU/δz) , close to very rough surfaces are reviewed and compared with field data discussed by J. R. Garratt. It is found for z/z 0 < 10 2 that Φ M < 1 in field data and > 1 in the wind tunnel experiments. This difference is discussed tentatively in terms of roughness element flexibility and porosity.