Proceedings of the 2016 International Conference on Education, Management, Computer and Society

Oxygen Transfer and Energy Dissipation by Nappe and Skimming Flow over Stepped Weir Structure

Authors
Jinhong Kim, Sunjung Kim, Min-Jee Li
Corresponding Author
Jinhong Kim
Available Online January 2016.
DOI
10.2991/emcs-16.2016.423How to use a DOI?
Keywords
Oxygen transfer; Energy dissipation; Nappe flow; Skimming flow; Stepped weir
Abstract

Oxygen transfer and the energy dissipation by the flow types at the stepped weir structure were performed through hydraulic experiments. Nappe flow occurs at low flow rates and for relatively small step slope. Dominant features of an air pocket, nappe impact and subsequent hydraulic jump occurs. At larger flow rates, skimming flow occurs with formation of recirculating vortices. Transition flow showed simultaneous occurrence of skimming flow at upper steps and nappe flow at lower steps. Air entrainment occurs through free-falling nappe impact and subsequent hydraulic jump in the nappe flow, and occurs from the step edges in the skimming flow. Energy dissipation occurs through the jet impact and the subsequent hydraulic jump in the nappe flow and occurs through maintaining the recirculation vortices between step edges in the skimming flow regimes. The average values of the oxygen transfer are 0.45 in the nappe flow and 0.28 in the skimming flow, and the efficiencies of energy dissipation in the nappe flow and in the skimming flow are about 70~95(%) and 60~90(%), respectively. From these results, the stepped weir structure is found to be efficient for oxygen transfer and for energy dissipation.

Copyright
© 2016, the Authors. Published by Atlantis Press.
Open Access
This is an open access article distributed under the CC BY-NC license (http://creativecommons.org/licenses/by-nc/4.0/).

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Volume Title
Proceedings of the 2016 International Conference on Education, Management, Computer and Society
Series
Advances in Computer Science Research
Publication Date
January 2016
ISBN
978-94-6252-158-2
ISSN
2352-538X
DOI
10.2991/emcs-16.2016.423How to use a DOI?
Copyright
© 2016, the Authors. Published by Atlantis Press.
Open Access
This is an open access article distributed under the CC BY-NC license (http://creativecommons.org/licenses/by-nc/4.0/).

Cite this article

TY  - CONF
AU  - Jinhong Kim
AU  - Sunjung Kim
AU  - Min-Jee Li
PY  - 2016/01
DA  - 2016/01
TI  - Oxygen Transfer and Energy Dissipation by Nappe and Skimming Flow over Stepped Weir Structure
BT  - Proceedings of the 2016 International Conference on Education, Management, Computer and Society
PB  - Atlantis Press
SP  - 1691
EP  - 1695
SN  - 2352-538X
UR  - https://doi.org/10.2991/emcs-16.2016.423
DO  - 10.2991/emcs-16.2016.423
ID  - Kim2016/01
ER  -