Improving drowned drainage outlets with submerged orifices
Drowned outlets are common in riverine areas and sometimes unavoidable. Due to site restrictions, drainage discharge outlets are often submerged as the water level fluctuates during high tides or during the monsoon. As the runoff cannot be discharged through the outlet the drainage system fills up...
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| Format: | Article |
| Language: | English |
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IWA
2016
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| Online Access: | http://ir.unimas.my/id/eprint/14766/ http://ir.unimas.my/id/eprint/14766/7/Improving%20drowned%20drainage%20outlets%20with%20submerged%20orifices%20%28abstract%29.pdf |
| Summary: | Drowned outlets are common in riverine areas and sometimes unavoidable. Due to site restrictions, drainage discharge
outlets are often submerged as the water level fluctuates during high tides or during the monsoon. As the
runoff cannot be discharged through the outlet the drainage system fills up faster, leading to flash floods caused
by overspill from the drains. This study is focused on the application of an on-site detention system with submerged
orifice to improve the runoff delay from a drowned outlet. The application was investigated through a
reduced-scale laboratory set up and then visualized with computational fluid dynamics simulations. The model
was tested under different perpendicular flow velocities to analyze the workability and flow characteristics of
the submerged orifice. The study showed that, with different headwater and tailwater levels, the energy level
can be restored upstream of the orifice and ensure full flow of water from the submerged orifice even when hindered
by perpendicular tailwater flow. Besides, the orifice jet’s pattern changes with high velocity tailwater flow,
although it does not slow down the discharge rate. |
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