Open AccessMobile layer in oscillatory sheet flow
Author(s) -
Flores Nicolas Zala,
Sleath John F. A.
Publication year - 1998
Publication title -
journal of geophysical research: oceans
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/98jc00691
Subject(s) - inertia , flow (mathematics) , materials science , pressure gradient , mechanics , layer (electronics) , anemometer , water tunnel , boundary layer , geology , flow velocity , turbulence , composite material , physics , classical mechanics , vortex
Measurements are reported of mobile layer thickness and the velocity and concentration distributions within the mobile layer in oscillatory sheet flow. Tests were carried out with sand, PVC, and acrylic granules in an oscillatory water tunnel. Velocities were measured with a laser Doppler anemometer, and concentrations were measured with conductivity probes. The measurements of mobile layer thickness appear to confirm the importance of the parameter S = (ρ U 0 ω/(ρ s −ρ) g ). At low values of this parameter the measurements tend toward the unique curve which would be expected if pressure gradient and inertia effects were negligible. On the other hand, the velocity profile measurements show some influence of pressure gradient and inertia even for values of S as low as 0.12. At higher values of S a type of plug flow is observed in which the sediment comes to rest as the flow reverses and then begins to move again as a solid block.