Analysis on power flow transmission of pressure fluctuation along the walls of hydropower house

For hydropower station,pressure fluctuation is a hydrodynamic loading with low and distributional frequencies that may induce resonances of some local structure of the powerhouse and hence influence structure safety.This paper presents a frequency response analysis of the full structure of a powerhouse,using the theory of power flow(PF),a PF-FEM method and the measured data of dominant frequency of spiral case and draft tube at the Three Gorges station under water head of 89.0 meter,focusing on computation of the power flow along the upstream and downstream walls of powerhouse with a procedure based on APDL coding.Results show that longitudinal waves are the major form of power transmission along the walls and that the transmitted energy is reflected and accumulated near the top of the walls.Further,the streamwise displacement of the walls varies in space,and the power flow decays with time considerably.The vibration strength of its source and the distance away from the source are two major factors of the transmission,and increasing the stiffness of the walls plays a positive role in reducing the transmission.