Experimental Studies of Heavy Radial Density Currents
Publication: Journal of Environmental Engineering
Volume 121, Issue 12
Abstract
Heavy-density currents occur when the inflow is denser than the ambient fluids in a basin. These currents exist in most secondary sedimentation basins. This paper investigates the internal flow regimes associated with the density currents due to cold influent entering circular clarifiers. The experimental studies included flow with unsteady influent temperature under different conditions of geometry, momentum, and negative buoyancy. Velocity and temperature of different flow regimes were measured throughout the basin. The flow phenomena progressed through a sequence of density flow regimes: the denser wall jet, internal hydraulic jump, rebound at the gate, and stratification. The data were analyzed to determine the characteristic depths, velocities, and isotherms for the radial density currents in a basin. This study shows that circular tanks subject to variable influent temperatures (or concentrations) experience internal surges in the form of moving hydraulic jumps. Depending on the tank geometry, this phenomenon could result in degraded performance of clarifiers during transient density events.
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Information & Authors
Information
Published In
Journal of Environmental Engineering
Volume 121 • Issue 12 • December 1995
Pages: 920 - 929
Copyright
Copyright © 1995 American Society of Civil Engineers.
History
Published online: Dec 1, 1995
Published in print: Dec 1995
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