Experimental Study of Energy Dissipation and Efficiency in a Stair-Shaped Modification of USBR Type III Stilling Basin

Abstract

The present study will attempt to investigate the energy dissipation in a stair-shaped stilling basin, developed as an improved model of the USBR Type III basin. For this purpose, an initial step of planning and modeling of the flume was undertaken, followed by experimental setup and data collection on the water level, critical depth, velocity, and discharge. In each of these two models, experiments were conducted for 10 variations in discharge. The energy dissipation ratio for the stair-shaped model reached 81.59%, as opposed to 78.99% for the USBR Type III. That means that the efficiency in the stair-shaped model is 2.6% higher. The velocity varied between 19.17 and 29.80 m/s for the USBR Type III model and between 17.42 and 28.14 m/s for the stair-shaped model. The maximum water level in USBR Type III was 'this', while in the stair-shaped model, it is +22.95, thus showing better energy dissipation. The stair-shaped model, also closely lies with the hydraulic jump state according to Elevatorski's formula and shows a value of 7% skewness. Further recommendations on topographic and geological conditions are warranted for the application of a stair-shaped basin.