Study on flow-induced vibration characteristics of air shield sluice based on hydrodynamic model

Due to its high efficiency and environmental friendliness, air shield sluices have been widely used in water release structure in recent years, the whole air shield system is composed of several steel gates and airbags, and some air shield sluice have a large span. The vibration problem of gate is particularly prominent for engineering safety, and its flow-induced vibration characteristics have not been clearly understood. To solve the problem of flow induced vibration in air shield sluice, in this paper, taking the sluice gate of Tacheng hydro project as an example, the pulsating pressure and flow pattern of the air shield gate are studied by the hydrodynamic model, and the three-dimensional simulation numerical simulation is carried out under the results of the hydrodynamic model. The natural vibration characteristics and vibration response characteristics of the air shield gate are analyzed through the study of hydrodynamic model and three-dimensional simulation numerical. The results show that:①The maximum fluctuating pressure of the gate under various working conditions is 4.22×9.81 kPa, the standard deviation of the fluctuating pressure is less than 0.1×9.81 kPa, the main frequency is less than 0.2 Hz, and the starting frequency of the gate is higher than 3 Hz, The possibility of vibration damage of the gate is not great; ②The vibration of the gate panel is mainly perpendicular to the direction of the panel. The maximum vibration displacement is 1.53×10^-6m, and the maximum vibration acceleration is 2.88×10^-3m/s². The vibration response of the gate under the action of fluctuating pressure is very weak. ③when the gate is partially opened, the upper half of the back plate is exposed to dynamic and reverse rolling water flow for a long time, and the air shield gate should be avoided to run for a long time in poor flow state. The research fills the gap in the air shield induced vibration test, and the results can provide reference for the design and safe operation of similar air shield dam projects.