Purpose

Vertical turbine pumps are used for critical application in power plant. Apart from power plant, these are also used in irrigation, water supply, process industries and petrochemical industries. Centrifugal and vertical turbine pumps consist of rotor geometry and a structure that can vibrate in response to excitation forces. Mass unbalances associated with mechanical and hydraulic geometry of a pump are the two major factors which create dynamic effects in terms of pump vibrations. The generated hydraulic forces resulting due to hydraulic unbalance have similar effect as of mechanical unbalance. For satisfactory operation of the pump, the vibrations in the pumps must be within acceptable limits of applicable standards. Higher level of vibrations not only leads to operational loss, but also leads to down time due to premature failure. Therefore, it is of vital importance for product designers to understand the dominating cause of unbalanced force and its source.

Method

The estimation of vibrations using numerical methods can help a designer, especially vibrations arising due to the hydro dynamic forces, for a successful design. In any centrifugal pump, including vertical turbine pump, there is always interaction between fluid and structure. Solid and fluid interaction in present case can be completed by one-way coupling method. The one-way fluid−structure interaction approach is presented in the present paper to predict the vibrations at specific operating conditions which have significant correlation with the test data. Similar philosophy has been applied for an impeller geometry which has hydraulic unbalance to predict the impact of hydraulic unbalance.

Results and Conclusions

The benefit of reduction in computational effort and time in this approach can be applied during the initial design stage. Two case studies of one-way FSI approach of a vertical turbine pump are discussed. The approach can be used for evaluating the impact of geometrical deviation, especially vane pitch in an impeller in terms of vibration displacements.

中文翻译：

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基于单向流体-结构相互作用的立式涡轮泵叶轮水力不平衡导致的水流振动预测

目的

立式涡轮泵用于发电厂的关键应用。除发电厂外，它们还用于灌溉，供水，加工工业和石化工业。离心式和立式涡轮泵由转子几何形状和可响应激振力而振动的结构组成。与泵的机械和液压几何形状相关的质量不平衡是在泵振动方面产生动态影响的两个主要因素。由于液压不平衡而产生的液压具有与机械不平衡相似的作用。为了使泵令人满意地工作，泵中的振动必须在适用标准的可接受范围内。较高的振动水平不仅会导致运行损失，还会由于过早的故障而导致停机。因此，

方法

使用数值方法估算振动可以帮助设计人员，尤其是由于水动力引起的振动，从而成功进行设计。在任何离心泵（包括立式涡轮泵）中，流体与结构之间始终存在相互作用。当前情况下的固液相互作用可以通过单向耦合方法完成。本文提出了一种单向流体-结构相互作用的方法，以预测在特定工作条件下的振动，该振动与测试数据具有显着的相关性。对于具有水力不平衡以预测水力不平衡的影响的叶轮几何形状，已经应用了相似的原理。

结果与结论

可以在初始设计阶段应用这种方法减少计算工作量和时间的好处。讨论了立式涡轮泵单向FSI方法的两个案例研究。该方法可以用于评估几何偏差的影响，特别是就振动位移而言，叶轮中叶片桨距的影响。