Laboratory Study and Comparison of Gabion Inclined Drop Energy Dissipation Equipped with Vertical Screens

Hydraulic engineers have always used applications in inclined drop to increase energy dissipation. In the present laboratory study, the simultaneous effect of the gabion and the vertical screens on the flow energy dissipation in the inclined drop structure was investigated. A total of 120 different experiments were performed for the flow range of 150 to 800 liters per minute and two heights, three inclination angles and two porosity ratios of vertical screens. The results show that in all models, the energy dissipation of the flow decreases with increasing the relative critical depth of the flow. The use of a vertical screens in a gabion inclined drop has little effect on flow energy dissipation, so that the average amount of increase in depreciation of the present study compared to a simple inclined drop equipped with vertical screens is 2.23%. The integrated system presented in the present study reduced the Froude number range from 1.66~2.11 to 0.83~1.9 compared to a simple inclined drop equipped with a vertical screen. A vertical screen with 50% porosity has a higher relative energy dissipation than a 40% porosity, and changing the inclination angle of a inclined gabion to the constant porosity of the screens does not cause much change in the amount of flow energy dissipation. Also, due to the low effect of the integrated system of the present study on the energy dissipation values of the flow, therefore, the simultaneous use of a vertical screens and inclined gabion is not economically recommended.