摘要
由于结构及流固耦合的复杂性,一直很难准确模拟水轮机转轮的动应力状态。利用双向流固耦合的方法,求得了水轮机转轮的动应力,得到了转轮运行中动应力的变化幅值。通过对结果的分析发现转轮应力和变形近似做周期变化,且周期和叶片与导叶个数有关。通过这种方法求出动应力后即可较准确预测转轮疲劳强度,也可对转轮在各个工况下动应力进行模拟,避免机组在转轮动应力较大的工况长期运行。同时对转轮固有频率及振型进行对比研究。相比在空气中,在水压力及离心力载荷作用下,转轮的固有频率下降约1%,这是由于水电机组刚度较强的原因,而在静水中下降较多。
Due to the complexity of structure and fluid-structure coupling, it is difficult to accurately simulate the stress state of the turbine runner. The dynamic stress of the turbine runner in running were obtained by using the two-way staggered fluid-structure coupling method By analyzing the results, it was found that the stress of the turbine runner was approximate periodicity and the periodicity has something to do with the number of guide vanes and the blades. After acquiring the dynamic stress, the fatigue strength could be accurately predicted, and the stress states under all working condition could be simulated. Meanwhile, the nature frequency and the vibration mode of the turbine runner were studied. Because of the greater structural stiffness of the hydroelectric generating set, the nature frequency under the water pressure and the centrifugal load was less about 1% than that in the air, and the decrease amplitude under still water had a more significant.
出处
《大电机技术》
北大核心
2014年第2期53-57,共5页
Large Electric Machine and Hydraulic Turbine
基金
国家科技支撑计划(2012BAF12B16-1)
关键词
双向流固耦合
转轮动应力
动态特性
水轮机
two-way staggered fluid-structure coupling method
dynamic stress of turbine runner
dynamic characteristic
hydraulic turbine
作者简介
李永恒（1983-），男，2009年7月毕业于西安交通大学流体机械及工程专业，研究方向为流体机械结构强度与振动，工程师。
