大型双吸离心泵叶轮动应力特性

基于顺序流固耦合理论,以双吸泵内部非定常流场信息作为力学边界条件,采用有限元方法,对一台大型双吸离心泵叶轮进行了瞬态动力学分析。主要考察了5个流量工况(0.6Qd、0.8Qd、Qd、1.1Qd、1.2Qd)下的叶轮动应力特征。结果表明,在不同流量工况下叶轮表面动应力分布趋势基本相似,最大应力点出现在叶片进口或出口边靠近前盖板的根部区域;在小流量(0.6Qd)工况下,动应力水平最高;叶片动应力随时间呈周期性变化;动应力频率成分主要为叶轮转频及其谐频。

Dynamic Stress of Large Double-suction Centrifugal Pump Impeller

The dynamic stress analysis for a large double-suction centrifugal pump impeller was presented by using the finite element method. This analysis was based on the sequential fluid-structure interaction theory. The pressure pulsation obtained from flow simulation by using CFD code was set as the force boundary condition. The dynamic stress characteristics of the impeller under five flow conditions (0.6Qd, 0.8Qd, Qd, 1.1Qd, 1.2Qd) were given. The results showed that the maximum stress of the impeller appeared at trailing edge or leading edge region of the blade near shroud. The stress distributions on impeller blade surfaces under different flow rate conditions are similar to each other. The level of dynamic stress under 0.6Qd is the highest. The dynamic stress varies periodically with the impeller rotating. It is also found that the fundamental frequencies of the dynamic stress are the rotating frequency and its harmonic frequency.