The Numerical Simulation Of Hydrodynamic Vertical Force Of Hydraulic Gate In Opening And Closing Process

Hydrodynamic vertical force(door water pressure,up-holding force,down-suction force) has a great influence on gate lifting force. Which at present,is mainly calculated by empirical equation or measured by physical mode test,however, some of the parameters in empirical equation are difficult to determine accurately,also some shortcomings such as incomplete collection of information ,scale effect ,interference flow field and time-consuming are existed in the mode tests. A 3D numerical model which combines the GMO method、RNGk-εturbulence model and VOF free surface treatment technology is adopted to simulate the hydrodynamic vertical force of the plane gate and the hydrodynamic vertical torque of the radial gate in the opening and closing process. Using this numerical simulation method mainly studied how the hydrodynamic vertical force and the hydrodynamic vertical torque change with the changes of different bottom shapes of gate and the variety of speed in the process of opening and closing the gate; analyzed the process line which recorded the changed hydrodynamic vertical force when opening and closing the gate.The research result of the paper is a highly valuable reference for designing the gate and determining the capacity of the hoist. With the hydraulic physical model test on the Jishixia Hydropower Station, the numerical simulation result has reasonable agreements with the experimental model results, which indicated that the numerical simulation was credible and has a higher precision. Some results are as follows:(1)This paper analyzes that how the hydrodynamic vertical force changes with the bottom shapes of gate and the variety of speed in the process of opening and closing the gate.The results show that increasing the angle in the downstream side can reduce the lifting force of the plain gate;decreasing the angle in the upstream side can reduce the closing force;increasing the opening speed of the plain gate can reduce the down-suction force and the lifting force; decreasing the opening speed of the plain gate can reduce the up-holding force and theclosing force.(2)Using the numerical simulation method anlyze the hydrodynamic vertical torque of the radial gate in the opening and closing process,we can obtained the change rule of the hydrodynamic vertical torque with gate relative opening degree. The results show that the smaller the dip angle of the radial gate, the smaller the peak of the down-suction force, in favour of reducing the lifting force; the smaller the dip angle of the reverse radial gate, the smaller the peak of the up-holding force,this case is reduced the closing force; decreasing the time of the opening and closing process can reduce the hydrodynamic vertical torque; increasing the time of the opening and closing process can increase the hydrodynamic vertical torque.