Determination of Discharge Coefficient on Linear Spillway and Multi Half-Circulars Spillway

The function of spillway is to overflow the excessive water discharge and to prevent the overlapping danger for other types of hydraulic constructions. A discharge flowing in the spillway is not only determined by the width of the specified crest, but also by other parameters, i.e., the geometry of the spillway crest consisting of width spillway, crest thick, and high spillway or a comparison between the energy and the spillway, as well as the discharge coefficient (Ca). The current figures of discharge coefficients are used in one form of spillway with the crest perpendicular to the flow. Hydraulic construction like spillway has been widely examined and a physical model has been built to ensure conditions that occur in accordance with the planning and can be operated separately. Based on the amount of the discharge flow and the flow energy spillway, research with different crests of the spillway was conducted. The types of spillway were multi half-circular spillway with four circulars (diameter of 11.4 cm) and linear spillway (width of 45.5 cm). This study indicates the better results of larger discharge flow and the lower water level in the upstream with the linear spillway.