عنوان مقاله [English]
The energy dissipation through hydraulic structure is an important issue in hydraulic engineering. The performance of hydraulic structure as a view of energy dissipation can provides the stabality of structure and river bed. In this study the experimental investigation of screen performance is evaluated as the energy dissipator of supercritical flow. The investigated parameters include: Froude number; screen porosity; location of screens. The Froude number of supercritical flow has been varied in the range of 2.5 to 8.5, and the screen porosities are 40 and 50%. Also the location of screens has been considered 62.5, 125 and 250 cm after supercritical flow generator gate. The results indicate that screen porosity, location of screens from supercritical flow generator gate and also Froude number of supercritical flow have a significant effect on screen performance. The energy dissipation of system through screens is more than free hydraulic jump in the entire evaluated cases. The results show that the Froude number increasing result in screen performance (relative energy dissipation) increasing, but screen efficiency (difference between the relative energy dissipation of system from free hydraulic jump) decreasing. Also the screen with 50 porosity which has been located at 125 cm from gate has the best performance.