Evaluation of gap influence on the dynamic response behavior of pump-turbine runner, 2018
Evaluation of gap influence on the dynamic response behavior of pump-turbine runner, 2018
复制标题
间隙对水泵水轮机转轮动态响应行为的影响评估，2018
DOI：
--
复制
发表时间：
--
影响因子：
1.6
通讯作者：
Sadao Kurosawa
中科院分区：
文献类型：
--
作者：
He Lingyan;Lingjiu Zhou;Soo-Hwang Ahn;Zhengwei Wang;Yusuke Nakahara;Sadao Kurosawa
转轮与邻近结构之间的间隙对转轮的动力响应起着重要的作用，特别是对于水泵水轮机。为了研究差距对水泵水轮机转轮附加质量和动应力的影响，提出了一种改进的转轮共振预测方法，采用声固耦合方法对一缩尺水泵水轮机转轮进行了不同轴向间隙和径向间隙的模态分析。采用基于声固耦合的单向流固耦合仿真方法计算转轮的动应力，并考虑了流体附加质量效应。通过在流固耦合面上采用网格匹配算法，将非定常CFD模拟得到的作用在转轮表面上的时变水压力作为边界条件传递到转轮结构上。结果表明，附加质量因子随差距尺寸的减小而增大。轴向间隙对同相（IP）模式的附加质量因子的影响大于反相（CP）和冠状主导（CD）模式，而CP和CD模式对径向间隙非常敏感。在（2+4）ND-CP模式（共振模式）中观察到最大的附加质量因子。结果表明，采用瞬态结构动应力分析方法可以准确预测共振现象。得到了水泵水轮机的共振曲线，并与试验结果进行了比较。差距流体对共振条件影响较大，而对于非共振工况点，间隙对动应力幅值的影响很小。本文为转轮设计阶段的动力响应分析提供了一种较为准确的方法。与以往通过模态分析或谐波分析预测转轮共振的方法相比，转轮共振曲线的预测具有更重要的意义。
The gaps between runner and nearby structures play an important role in the dynamic response of runner, especially for pump-turbines. The paper aims to evaluate the gap influence on the added mass and dynamic stress of pump-turbine runner, and provides an improved method to predict the resonance of runner.Acoustic-structural coupling method was used for the modal analysis of a reduced scale pump-turbine with different axial and radial gap size between runner and nearby rigid walls. One-way fluid-structural interaction (FSI) simulation based on acoustic-structural coupling was used to calculate the dynamic stress of the runner, which taken into account fluid added mass effect. The time-dependent hydraulic forces on the runner surfaces that obtained from unsteady CFD simulation were transferred to the runner structure as a boundary condition, by using mesh-matching algorithm at the FSI surfaces. The results show that the added mass factors increase as the gap size decrease. The axial gaps have greater influence on the added mass factors for the in-phase (IP) modes than counter-phase (CP) and crown-dominant (CD) modes, while the CP and CD modes are much sensitive to the radial gaps. The largest added mass factor is observed in (2+4)ND-CP mode (resonance mode). The results reveal that using transient structural dynamic stress analysis method can accurately predict the resonance phenomenon. Resonance curve of the pump-turbine has obtained which is confirmed well agree with the test result. The gap fluid has great influence on the resonance condition, while for non-resonance operating points, the effect of gaps on the dynamic stress amplitude is quite small. This paper provides an accurate method to analyze the dynamic response during runner design stage for safety assessment. The resonance curve prediction has more significance than previous methods which predict the resonance of runner by modal or harmonic analysis.