Hydroelectric Power Plant Trashrack Design

Abstract

Trashracks subjected to high velocity flow should be designed to avoid operating under resonant conditions. This requires that design consideration be given to the natural frequency of the trashrack bars and the forcing frequency due to the velocity of the fluid through the trashrack. The natural frequency of a trashrack bar is primarily dependent upon the material, cross sectional configuration, unrestrained length and the end fixity. The forcing frequency, due to flow considerations, is primarily dependent upon the velocity of the fluid and the cross sectional configuration of the bar. The fundamental consideration is to design a trashrack with the natural frequency of the bars sufficiently higher than the forcing frequency to prevent a resonant condition from developing.