大型水轮机不稳定流体与结构耦合特性研究Ⅱ：结构动应力与疲劳可靠性分析  

Analysis on unsteady fluid-structure interaction for a large scale hydraulic turbine Ⅱ. Structure dynamic stress and fatigue reliability

作　　者：王福军[1] 赵薇 杨敏[1] 高江永[1] 

机构地区：[1]中国农业大学水利与土木工程学院,北京100083 [2]Norwegian University of Science and Technology, NO-7491 Trondheim, Norway

出　　处：《水利学报》2012年第1期15-21,共7页Journal of Hydraulic Engineering

基　　金：国家自然科学基金项目(90510007,91010003);北京市自然科学基金重点项目(3071002)

摘　　要：水轮机疲劳寿命问题直接关系到电站安全和工程效益的发挥。本文以国内某大型水电站安装的混流式水轮机为研究对象,通过引入新的耦合界面模型,实现了不稳定压力场与结构场的耦合特性分析。耦合计算采用有限元方法,得到了转轮在不同工况下的压力脉动载荷的时间历程。通过雨流计数法处理,获得了应力幅值及均值的概率密度函数。依据材料疲劳特性预测了转轮叶片的寿命。文中还分析了X形叶片转轮在运行稳定性方面所具有的特征。所取得的研究结果为大型水轮机的稳定运行和优化设计提供了依据。The fatigue reliability has significant effects on power plant safety and engineering benefit. By introducing a new coupled interface model, a Francis turbine installed at a large power plant in China is investigated through the unsteady fluid-structure interaction （FSI） analysis. The finite element method is adopted to solve the FSI problem. The dynamic stress of runner blade is presented in time domain and frequency domain in detail. A joint stress distribution density function describing the mean stress and amplitude is established with statistics method, including the rain flow counting algorithm. According to the fatigue properties of the blade material and the fatigue reliability model, the blade fatigue life is predicted. The operation stability of the runner with X type blade is also analyzed. The results are meaningful to stable operation and optimized design of large hydraulic turbines.

关 键 词：水轮机 流固耦合 叶片 动应力 疲劳可靠性 

分 类 号：TK730.2[交通运输工程—轮机工程]