On the basis of analysis the governing process of downstream water level gates AVIO and AVIS, a mathematical model for simulation of dynamic operation process of hydraulically automated irrigation canals instalIed wit...On the basis of analysis the governing process of downstream water level gates AVIO and AVIS, a mathematical model for simulation of dynamic operation process of hydraulically automated irrigation canals instalIed with AVIO and AVIS gates is presented, the main point of this rnathematical model is firstly applying a set of unsteady flow equations （St. Venant equations here） and treating the condition of gate movement as its dynamic boundary, and then deeoupling this interaction of gate movement with the change of canal flow. In this process, it is necessary to give the gateg open-loop transfer function whose input is water level deviation and output is gate discharge. The result of this simulation for a practical reach has shown it has satisfactory accuracy.展开更多
For an emergency gate in a surge tank, the forces acting on the gate were systematically tested and analyzed, including pulling forces resulting from water hammer because of the sudden rejection of all loads in turbin...For an emergency gate in a surge tank, the forces acting on the gate were systematically tested and analyzed, including pulling forces resulting from water hammer because of the sudden rejection of all loads in turbine units under different gate levels and forces during the process of gate shutoff under the conditions of different numbers of running turbine units. Besides, for the pulling forces on the top of gate, their variation processes with time and extent of gate opening were also tested. It is shown that the calculated value of the gate pulling force agrees on the whole with its tested one. The results indicate that the emergency gate in the extraordinary large surge tank of WWS hydropower station is safe under the above test conditions. The related data in the present paper are helpful for the study of the emergency gate in a surge tank.展开更多
Starting with field investigation this paper presented a comprehensive review of the hydraulic design and performance of gate slots in 85 existing projects covering 158 gates of various dimension and operating head. S...Starting with field investigation this paper presented a comprehensive review of the hydraulic design and performance of gate slots in 85 existing projects covering 158 gates of various dimension and operating head. Systematic model tests were conducted in a water tunnel to optimize the configuration of gate slots. Main parameters affecting cavitation inception were studied, such as the ratio of width to depth, relative offset, the slope of side wall, as well as the radius of curvature of slot's corner. The scale effects of cavitation modelling were preliminarily verified. The conformity between model studies and prototype inspections is quite agreeable. Conclusion and suggestion were made to meet the demand of hydraulic design of gate slots.展开更多
基金Supported by the 863 Programof China (2001AA242111)
文摘On the basis of analysis the governing process of downstream water level gates AVIO and AVIS, a mathematical model for simulation of dynamic operation process of hydraulically automated irrigation canals instalIed with AVIO and AVIS gates is presented, the main point of this rnathematical model is firstly applying a set of unsteady flow equations （St. Venant equations here） and treating the condition of gate movement as its dynamic boundary, and then deeoupling this interaction of gate movement with the change of canal flow. In this process, it is necessary to give the gateg open-loop transfer function whose input is water level deviation and output is gate discharge. The result of this simulation for a practical reach has shown it has satisfactory accuracy.
文摘For an emergency gate in a surge tank, the forces acting on the gate were systematically tested and analyzed, including pulling forces resulting from water hammer because of the sudden rejection of all loads in turbine units under different gate levels and forces during the process of gate shutoff under the conditions of different numbers of running turbine units. Besides, for the pulling forces on the top of gate, their variation processes with time and extent of gate opening were also tested. It is shown that the calculated value of the gate pulling force agrees on the whole with its tested one. The results indicate that the emergency gate in the extraordinary large surge tank of WWS hydropower station is safe under the above test conditions. The related data in the present paper are helpful for the study of the emergency gate in a surge tank.
文摘Starting with field investigation this paper presented a comprehensive review of the hydraulic design and performance of gate slots in 85 existing projects covering 158 gates of various dimension and operating head. Systematic model tests were conducted in a water tunnel to optimize the configuration of gate slots. Main parameters affecting cavitation inception were studied, such as the ratio of width to depth, relative offset, the slope of side wall, as well as the radius of curvature of slot's corner. The scale effects of cavitation modelling were preliminarily verified. The conformity between model studies and prototype inspections is quite agreeable. Conclusion and suggestion were made to meet the demand of hydraulic design of gate slots.
