Minimising interference of hydraulic jump with hydraulic gates

Hydraulic gates are hydraulic control equipments to control the flow of water in any water resources project. The location of horizontal girders are influenced by type of hydraulic loading, fixity of it with gate and interference of hydraulic jump formed downstream of gate. When a high-head vertical lift gate is opened with a small opening, a hydraulic jump forms downstream, which interferes with the bottom-most horizontal girder. In the present paper, an attempt has been made using numerical experiments to highlight the effect of interference of hydraulic jump on horizontal girders of vertical lift hydraulic gate. For the numerical experiments, the design thickness of gate as 1.2m with water head (H) as 13.7m (without tail water) is considered. Hydraulic jump profiles for gate openings 0.05, 0.1, 0.2, 0.3, 0.4 and 0.5m have been discussed. The methodology adopted leads to a bottom slope estimation which for a water pressure head of 13.7m and a vertical lift gate of thickness 1.2m leads to a bottom slope 30°. Thus, this work provides a preliminary basis for minimising interference effects in fixing the bottom-most horizontal girder under high heads, dealing with an important field problem that has not yet been tackled to a satisfactory level. © 2013 Indian Society for Hydraulics.