Experimental Modeling of Hydraulic Characteristics in Stiling Basin USBR Type III

The paper presents the hydraulic performance on the USBR Type III Stilling Basin Model. The USBR stilling basin type III is widely used to construct reservoirs with low hydrostatic pressure and discharge rates. The hydraulic characteristics, like possible jump types, pressure regimes, and forces acting on the sill, aren’t considered. This research aimed to determine the effect of tailwater conditions on water level (y1 and y2), length of the basin (Lj), Froude number (Fr), critical depth (yc), and the effectivity of dissipation energy (ΔE). The results of this study show that the average energy dissipation ratio of the USBR Type III Stilling Basin without the influence of Tailwater is 87.45%, while the efficiency is 12.55%. The average energy dissipation ratio of the USBR Type III Stilling Basin with the influence of Tailwater is 69.47%, while the efficiency is 30.53%. The water level elevation without Tailwater is lower than that using Tailwater conditions. With a Froude Numbers (Fr2) value of 0.22 (<1), the flow condition with Tailwater is subcritical flow.