Modeling Sediment‐Induced Density Currents in Sedimentation Basins
Publication: Journal of Hydraulic Engineering
Volume 113, Issue 1
Abstract
Sediment‐driven density currents exist in most secondary sedimentation basins and cause the usual hydrodynamic flow pattern in these basins to deviate substantially from uniformity. The mathematical model introduced here allows one to predict, by direct computation, the behavior of the bottom current and the surface return flow, and simultaneously to determine their distributional effects on the sedimentation process itself. The model consists of conservation equations for fluid mass and momentum and sediment volume, supplemented by a modified form of the turbulence closure model. This paper emphasizes the description of features of the model and the presentation of results for a set of flows that may occur in a typical circular secondary clarifier. These results include the flow pattern, concentration distribution of sediment, the percentage of solids removal, and some examination of turbulence quantities in the basin. Some model sensitivity studies are reported.
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Information & Authors
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Published In
Journal of Hydraulic Engineering
Volume 113 • Issue 1 • January 1987
Pages: 80 - 94
Copyright
Copyright © 1987 ASCE.
History
Published online: Jan 1, 1987
Published in print: Jan 1987
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