Researches On Property And Numerical Calculation Of Flow-induced Vertical Vibration Of Plate Gate

The gate which control shutting and opening of the draining is an importantcomponent of hydraulic structure. The gate may experiences self-excited vibrationwithin some reduced velocity when the gate opening is very small and there is a waterhead between upper and lower. Self-excited vibration is a very complicatedfluid-structure interaction. The gate may be damaged because of fatigue if the gateundergoes vibration in a long time. The gate may even undergo resonance anddestabilization in some conditions.The paper researches self-excited vertical vibration of the plane gate and itsmechanism, also researches stability of vertical gates and gives stability index.First of all, the paper researches vortex-induced vibration of plane gate usingmodified wake oscillator model. The merit of modified wake oscillator model is thatthere are less experiential parameters by putting add mass item into the model anddecomposing add damping into viscous fluid damping and negative damping.Because of the merit the modified wake oscillator model can describe thevortex-induced vibration of plane gates in resonant regions and increase the precision.The calculated results agree the experiment results well.Next the paper divides self-excited vertical vibration of plane gates into twotypes: galloping and vibration due to discharge fluctuation and inertia and researchesthe stability of the two mechanisms respectively. The paper puts importance onto theScruton number influence to the vibration stability and gives stability index finally.Finally, the paper researches self-excited vertical vibration of plane gates bynumerical simulation method using finite volume method for dispersing and usingLES as turbulent flow model and draw Newmark HHT method into structure modelcalculation. The grid is divided by Immersed Solid FSI method which is based ontogrids overlapping technology. The conditions of different opening and reducedvelocity are calculated. The calculated results agree well with experimental results.Then Self-excited vibration mechanism of gate is analyzed deeply by calculatedresults. The results introduce that increasing rigidity and density is a good method toreduce possibility of self-excited vibration of plane gates.