OPTIMAL POSITION OF CURVED DEFLECTOR TO MINIMIZE SCOUR DOWNSTREAM MULTI-VENTS REGULATORS

Recently, it is planned to redesign and construct major hydraulic structures such as New Esna, and New Naga Hammadi Barrages. The design of these multi-vents structures was carried under the submerged hydraulic jump conditions. These huge structures face a great harmful caused by local scour downstream (DS) their stilling basins. An experimental program was carried out on multi-vents regulator laboratory model provided with curved deflector as an energy dissipation device. The curved deflector was carefully designed to be located at pre-specified positions in the basin. The scour dimensions DS of the stilling basins was measured. Also, the velocity near to bed was measured by electromagnetic flowmeter at different positions along both the basin and the channel bed to enable better understanding of the physical process associated with the phenomena being investigated. The dimensional analysis was used to initially correlate the relevant parameters to both the relative scour depth and the relative velocity near the bed. The effects of flow submergence, Froude number, operation policy and position of deflector on the scour dimensions and on velocity distribution nearby were investigated. The curved deflector proved to be an effective tool for controlling local scour DS multi-vents regulators as the local scour DS the stilling basin which was reduced on the average by about 85% using this effective tool.