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The propagation of modified flow downstream of a change in roughness
Author(s) -
Jackson N. A.
Publication year - 1976
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.49710243420
Subject(s) - surface finish , mechanics , boundary layer , downstream (manufacturing) , wind tunnel , plume , flow (mathematics) , planetary boundary layer , meteorology , roughness length , surface roughness , upstream (networking) , materials science , wind speed , geology , physics , wind profile power law , engineering , composite material , telecommunications , operations management
Abstract Using published atmospheric and wind tunnel data from a variety of sources, it is established that the rate of propagation of modified flow downstream of a change in surface roughness is determined essentially by the rougher surface. For the data examined neither the ratio of the upstream to downstream roughness lengths nor the ratio of boundary layer height to roughness element height is of itself a significant parameter. Based on an empirical analogy with Kazanskii and Monin's plume propagation concept, a simple method is proposed for predicting the depth of modified flow. The predictions include an origin correction and are shown to agree satisfactorily with measurements in neutrally stratified boundary layers.