Research On Dynamic Characteristic And Flow-induced Vibration Of Radial Gate

Radial gates are widely used in hydraulic buildings, but some safety and stability problems exist in its application because of the complexity of structure and working condition.It is of great practical value and significance to study the dynamic characteristic and flow-indued vibration of radial gates.Based on these problems, and with the project of Longtan bottom radial gate as its background in engineering practice, the dynamic characteristic and the problems of flow-induced vibration of radial gate are studied by means of both experimental and numerical methods.By using the hydro-power model, the informations of fluctuating pressure in radial gate are achieved and the characteristic of hydrodynamic pressure in radial gate is studied and some general laws are acquired. By using hydro-elastic model , the static&dynamic stress, nature frequencies and acceleration of the measuring points on the radial gates are tested .furthermore, the rules of static stress distribution, the autooscillation characteristic and dynamic response of the radial gates are studied.With the software ANSYS, the FEM model for Longtan bottom radial gate is established. The gate's static circumstance is studied and the results are compared with that of the model test, which prove the reliability of the two methods.The rules of stress distribution and deformation of the main components of the radial gate are further analyzed.Fluid-solid coupling is a difficult problem in the study of dynamic characteristic for radial gates. Westergaard (1933) had studied water pressure on dams during earthquakes.Based on this idea, according to Westergaard expressions, the attached mass due to fluid-structure coupling motion is applied on the surface of the radial gate by the author's program by finite element method. The nature frequencies of the radial gate in the water, as well as in the air, are calculated, the model is analyzed, and the influences by the attached mass on the radial gate and boundary conditions are discussed.Finally, combined with productive tasks, some suggestions are provided for the optimum design and safe operation for Longtan bottom radial gate.