2006 Volume 50 Pages 835-840
De Marchi proposed a discharge formula of the side-weir. However, the discharge coefficient which is included in the discharge formula was not clear quantitatively. After his study, a lot of researches have been conducted to investigate on the discharge coefficients. Sabramanya & Awathy found that the parameters of the discharge coefficient are four ones, i.e., the inlet Froude number, the ratio between the height and length of the weir, the ratio between the inlet flow depth and length of the weir and the ratio between the length of the weir and channel width, by the dimensional analysis. Several discharge coefficients in subcritical open-channel flows were suggested. However, systematic experiments in supercritical open-channel flows have not been conducted. In this study, systematic experiments were conducted under the condition that the height of the side-weir was set to zero. A new discharge coefficient of the side-weir with zero height in supercritical open-channel flows is proposed.