Discharge Coeficient Analysis according to Flow Condition for Radial Gate Type

Radial Gate 형식의 배수갑문 흐름조건별 유량계수 검토

Gates for the purpose of drainage are classified following the types of structure as: Radial Gate, Sluice Gate, Rolling Gate, Drum Gate. In many cases of the reclamation project the sluice type of gates are applied. Different from this general trend, however the radial type of gate was adopted in the Saemangeum project. In this case the discharge coefficients which are used for the sluice type of gate was applied. To estimate the correct amount of discharge which will be evacuated through the gates, therefore the proper discharge coefficients should be estimated before the operation of the gates. The discharge coefficients were estimated through the physical hydraulic modeling, and we got the results as: $0.72{\sim}0.84$ for the submerged condition on the both sides of upstream and downstream, $0.62{\sim}0.83$ for the free surface condition on the downtream side only, and $1.04{\sim}1.12$ for the free surface condition on the both sides of upstream and downstream. The discharge coefficients obtained from the experiments are greater than those of the sluice gates in the design criteria. From the results of the study we may expect that in the Saemangeum project the radial gates could evacuate larger amount of discharge than the originally designed discharge, so that we may sure that the Saemangeum gates have enough capability to control the evacuation of water not only in the usual period but also in the flooding season.