Baishan Pumped Storage Pumping Trash Rack Trash Rack Flow-induced Vibration Of Hydroelastic Model Pilot Study

1. A brief introduction is described which indudes the state of the art of research and design about the trashracks of conventional and pumped-storage hydroelectric plants, the necessary to research the flow-induced vibration of the trashrack bar by use of hydro-elastricity similaymodel and the background of this study.2. According to the gravity-elasticity similar law the model scale of Bai Shan pumped-storage hydroelectric plants is taken as The trashrack bar is made of Zinc, the relative errorsbetween its practical density and elastic modulus and its proper values are -7.82% and +1.43%, respectively. By LVS measuring the velocity distribution ahead the trashrack bar and on the basis of the velocity distribution the working conditions of the pumped-stroage hydroelectric plant are controled. The dynamic strain of the trashrack bar induced by flow are measured using strain slips.3. The velocity distributions and the strain duration curves measured are given and the spectrum density curves corresponding to the strain durations are given also. It is shown that during generating operation the maximum strains are subject to variation from 26 y. e to 38 y. with velocity from 0. 94m/s to 1. 32m/s. The spectrum measured at the middle point of the bar show a single peak at the frequency about 21Hz but multi-peaks at the fixed end of the bar . During pumping operation the maximum strains are subject to variation from 17 V- e to 22p e with velocity from 0. 96m/s to 1. 25m/s and there is no evident peak shown on the spectrum curves.4. The natural vibration spectrum curve is measured and the critical velocity to induce trashrack bar galloping is calculated. The effect of bar spacing on the bar strain and the characteristics of the exciting force are discussed. By fatigue analysis it is obtained that the service life of weld at the fixed end of the bar is about 13. 6 years.