摘要
脉动压力是水电站运行中的水力动荷载,其频率分布范围较广且频率值较低,容易与厂房局部结构产生共振而影响厂房安全。本文基于功率流理论及功率流有限元方法,借用三峡电站89m工作水头下的实测蜗壳尾水管脉动压力数据,对优势频率下厂房整体结构进行频响分析,编制APDL程序计算上下游墙体传导的功率流。结果表明,纵向波能量传导是厂房墙体能量传导的主要形式,且纵向传导的能量具有反射叠加特性,在墙体顶部出现极值。此外,墙体顺河向位移变形明显,功率传导具有明显衰减特性,振源强度、墙体与振源的净距是振动能量传导的主要影响因素,增加墙体刚度对限制功率流传导有积极作用。
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.
出处
《水力发电学报》
EI
CSCD
北大核心
2013年第2期233-239,共7页
Journal of Hydroelectric Engineering
基金
国家自然科学基金(51079020)
关键词
水工结构
功率流
谐响应分析
厂房墙体
传导路径
hydraulic structure
power flow
harmonic response analysis
walls of hydropower house
transmission path
