Study On Vortex In Front Of Radial Gate And Its Influence On Panel Load

Problem of vortex,which commonly arise at hydraulic intakes,has an adverse effect on the operation of the projects.At present,the generation mechanism and hydraulic characteristics of vortex has been researched through theoretical analysis,physical model experiment and numerical simulation,but previous studies mainly focused on intakes such as and spillway tunnels,there is insufficient research on the vortex in front of the gate when the gate is opening.In order to solve the problem of vortex,ensure the safety of the projects,the relevant experiment study and theoretical analysis are made with large hydraulic model.The main research content and conclusion are as follows:(1)Taking a flood sluice gate as a prototype,a large hydraulic model is made for experiment about the hydraulic characteristics and influential factors of vortex.The study shows that the influential factors of the suction vortex mainly include: the water depth of the radical gate,the gate opening,the circulation and the velocity of the water flow.The critical submergence of the suction vortex in front of the partially opened radial gate has two limitations,when the submergence of the intake is between the two limitations,there will occur air-core vortex.When the gate opening greater,the vortex stronger.(2)The hydraulic characteristics and the formation of vortex in the continuous gate opening process are qualitatively analyzed.And the relative opening e/H is used as standard to divide this process into two phases: when e/H<0.3,there is no vortex;while e/H>0.3,is the air-core vortex generation stage.(3)Taking the pulse pressure of the gate panel and the gate holding force as the main research objects,to analyze how the vortex influence the operation of the gate.By measuring the gate panel pressure and the holding force when the vortex occurs,use the EMD to obtain the gate panel pulse pressure data,and the wavelet function is used for further time-frequency analysis of the pulse pressure.The analysis showed that when a vortex appears in front of the gate,there is correlation between vortex intensity and pulse pressure characteristics,the stronger the vortex,the closer the gate is to the air-core,the more affected by the vortex.