Study On The Flow-induced Vibration Characteristics Of Radial Gate And Its Structural Optimization

With the flourish development of the hydropower project in China, the scale ofhydropower project becomes more and more large and significant. The safety of thehydraulic structures has been put more and more attention. The safety and the normaloperation of the hydraulic gate are of great importance to the whole hydroproject. Inthe process of lifting and closing, or at local opening conditions, gate vibrations arepossible, and the cause or style of the vibration is multiplicate. The service gate of thewater release structure introduces radial gate currently. Furthermore, it has beenapplied widely because of its merits such as, low lifting force, no gate shot, good flowpattern, and convenient operation etc. So it has great meaning to develop a study onthe dynamic characteristics of the hydraulic radial gate.In this paper, taking Xinzheng Hydraulic Project on the Jialing River as anexample, the researches on model testing and numerical simulating about dynamiccharacteristics and optimizations of the water release radial gate were carried. Themain studies are as follows:(1) A hydro-elastic model was developed on the basis of its simulation theory andtesting requirement. And also the dynamic loads characteristics and results offlow-induced vibration were analyzed.(2) A three-dimensional finite element model for the radial gate was established byusing the ANSYS Finite Element Software. Then the natural vibration frequencywas calculated, and the effect of the fluid-structure coupling on its naturalvibration property was also analyzed. Through the numerical calculation on theflow-induced vibration according to the hydrodynamic loads from model test, thedynamic safety of this gate was analyzed, and several suggestions were proposed.(3) The structural buckling of radial arms both static and dynamic was analyzed.According to the studies on the factors, which affect the space buckling loads ofthe radial arms, we found the best configuration on the radial arms. Based on thecharacteristics of hydrodynamic loads on the radial gate, the dynamic stability ofthe radial gate was analyzed, the equation of its critical frequency was deduced,the dynamic-stability district and dynamic-instability district was ascertained Atlast, based on the radial gate of Xinzheng Hydraulic Project, we analyzed thedynamic stability of this gate arm.(4) Using the optimization method of mathematics, we applied the structuraloptimization methods to the radial gate main frames design. Meanwhile, we gotsatisfying structural configuration when putting the genetic algorithm to itsoptimize design and considering the static and dynamic restriction conditions.