基于流固耦合的导叶式离心泵强度分析

运用顺序耦合和双向流固耦合方法对导叶式离心泵进行了强度分析。通过顺序流固耦合方法，对叶轮进行了静应力强度分析，并与双向流固耦合方法得到的结果进行了比较。同时，对双向流固耦合结果中最大等效应力节点A和最大变形区域的节点B在叶轮旋转一周过程中的等效应力变化的时域图以及频域图进行了分析。结果表明，最大等效应力出现在叶轮前盖板、叶片背面和叶轮出口边的交界处（节点A）；叶片进口边中部以及与前后盖板的交界处和叶片出口与后盖板的交界处这些地方有应力集中，可能发生强度破坏。后盖板出口处且正好在流道中部位置变形最大（节点B），可能发生刚度破坏。对于静力学分析，顺序耦合与双向耦合的结果基本一致。节点A的变形量小于节点B，但交变应力的幅值却远大于节点B。疲劳裂纹的扩展速度主要取决于交变应力幅值的大小，因此，在节点A处更易发生疲劳破坏。计算结果对导叶式离心泵叶轮结构优化设计提供了有效依据。

Strength Analysis of Diffuser Pump Based on Fluid-structure Interaction

Sequential coupling and strong fluid-solid coupling method were used to analyze the intensity of diffuser pump. Compared with the result of strong fluid-solid coupling, the static structural stress of impeller was analysed with sequential coupling method. Then the variation and frequency spectra of equivalent stress on node A that is the maximum equivalent stress of all was discussed during a cycle of the impeller. The maximum deformation node B was also calculated. The results indicate that the node A of maximum equivalent stress is found at the junction of shroud, suction side of blade and outlet of impeller. The intensity failure may happen at these places that have stress concentration. For example, in the middle of inlet side of blade; the junction of the inlet or outlet side of blade, shroud and hub. Stiffness damage may take place in the middle of impeller passage’s outlet side which node B located, because these places have a large deformation. Although the deformation of node A is less than node B, the alternating stress of node A is larger than node B. Because of the failure criteria in fatigue determined by the amplitude of the alternating stress, the fatigue failure is more likely to happen at node A. The results can provide effective references to the structural optimization design for the impeller of diffuser pump.