HYDROELASTIC MODEL STUDY ON FLOW INDUCED VIBRATION OF A TAINTER GATE FOR THE THREE GORGES PROJECT

摘要

The potential vibration problem of the radial gate at a bottom outlet of the Three Gorges Project (TGP) is greatly concerned by the designers since the gate is unavoidably operated under a drown-discharge condition in a flood season. This paper presents the investigation on the flow induced vibration of the gate by means of the hydroelastically similar model. It briefly introduces the hydroelastically similar criteria for the gate vibration, the properties of the hydroelastic similarity material we developed, the modal analysis results of the gate model and the results of hydraulic tests with a 1:20 scaled hydroelastic gate model. The experimental results show that a severe self-excited vibration of the gate will occur under the drown-discharge condition and with no side seals or side seals damaged. When blocking the two side gaps of the gate only weak vibrations take place under the same drown-discharge condition as mentioned above. The reason for the severe gate vibration is the joint effect of both the side leakage flow and the downstream turbulent flow. When making the side seal leakage stop, the severe vibration of the gate could be avoid.