OXYGEN TRANSFER BY FLOW CHARACTERISTICS AT STEPPED DROP STRUCTURE - Advances in Geosciences - page 135

skimming flow because air entrainment is made mainly through a free-
falling nappe impact, a hydraulic jump and an air pocket in the region of
nappe flow. The average values of the oxygen transfer eciency in the region
of the nappe flow and in the region of the skimming flow are about 0.45
and 0.28, respectively. The stepped drop structure is found to be ecient
for water treatment associated with substantial air entrainment.

Acknowledgments

This research was supported by the Chung-Ang University Research Grants
in 2004.

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