Author(s): Seung Sook Shin; Jaebin Seonwoo; Yukyeong Lee And Joongcheol Paik
Linked Author(s): Seung Sook Shin, Joongcheol Paik
Keywords: Uxiliary spillway Ogee spillway Discharge coefficient Hydraulic experiments Rating curve
Abstract: Physical hydraulic modeling test is often employed to estimate the relationship between water depth and discharge and ensure structural stability from shock wave and cavitation damage problems with the operation of the dam auxiliary spillway during a flood. This study established an experimental model of a 1:20 scale to identify the flow characteristics and rating curves of the tunnel-type auxiliary spillways and ogee spillways of the Hwacheon Dam, Korea. The orifice-discharge equation was applied to the outlet conduit of the auxiliary spillway and the weir-discharge equation was applied to the rectangular channel of the ogee spillway. The discharge coefficients were analyzed separately depending on the opening of the sluice gate of the ogee spillway and the presence or absence of a flow deflector installed near the outlet of the auxiliary spillway. Additionally, the effects of the conduit gate's opening rate and the air vent's opening-closing conditions on the discharge and flow features in the auxiliary spillway were examined. The discharge coefficients increased by 12.5% after installing the deflector and 25.2-40.3% after opening the air vent. The discharge coefficients in the auxiliary spillway generally decreased by the opening of the sluice gate of the ogee spillway. The outflow efficiency in the outlet conduit was reduced due to obstruction of overflow from the ogee spillway.
Year: 2025