Analisis Jenis Aliran Dan Tipe Loncatan Pada Pintu Sorong Saluran Sekunder

Abstract

This study analyzes flow type and hydraulic jump type in a secondary channel based on the Froude number as the main parameter. The study used secondary data from a previous investigation by Sunik (2001) to examine the flow characteristics occurring through a sluice gate. The results show that in Channel 1, increasing discharge caused an increase in the Froude number, resulting in critical and supercritical flow conditions, with hydraulic jump types classified as undular and weak jumps. These conditions were particularly observed in sections 2, 3, and 4. In the other sections, the flow was subcritical (Fr<1) and no hydraulic jump occurred. For water levels of 40–90 cm, the Froude number tended to decrease and approach 0.5, indicating subcritical flow without a jump. In contrast, at water levels of 10–30 cm, the Froude number increased and approached 2, indicating critical and supercritical flow accompanied by undular and weak hydraulic jumps. For flow velocities of 50–200 cm/s, the Froude number decreased and approached 1, indicating subcritical flow without a jump. For velocities of 250–400 cm/s, the Froude number increased and approached 2, indicating critical and supercritical flow. Based on the allowable flow velocity limit of 2 m/s, velocities of ≤ 200 cm/s in Channel 1 are considered safe because they remain in subcritical conditions and do not cause downstream erosion. In Channel 2, the analysis also shows that increasing discharge leads to an increase in the Froude number, with critical and supercritical flow conditions and undular and weak hydraulic jumps occurring in sections 8–9. In the other sections, the flow remains subcritical and no hydraulic jump occurs. In general, as water depth increases, both the Froude number and flow velocity decrease; conversely, as water depth decreases, both the Froude number and flow velocity increase