基于流固耦合的水轮机转轮应力数值模拟

发布时间：2018-01-18 02:29

本文关键词：基于流固耦合的水轮机转轮应力数值模拟　出处：《华中科技大学》2015年硕士论文　论文类型：学位论文

【摘要】：转轮是水轮机组的核心部件,转轮的安全性直接关系到水电机组的长期稳定运行。传统的实验测量方法虽具有较高的准确性和实用性,但成本很高,需要消耗大量的人力物力以及时间。运用基于流固耦合的应力模拟技术,可以在低成本下从一定程度上得出应力的大致分布情况,为转轮应力的进一步研究指明方向。基于starccm+有限元分析软件,对三峡左岸电厂6号机组进行了计算流体力学模拟分析,得出其水力模型内流情况和外特性参数,与相应实验数据进行对比验证流场模拟的可靠性。运用流固耦合数值模拟技术,截取转轮中一个叶片进行结构模拟分析,得出叶片表面应力分布、应变量分布,并对照实验测点在叶片表面取若干节点与相应实验数据进行对比,验证了数值模拟结果的可靠性,同时对数值模拟的不足之处也进行了适当分析。进而对模型进行流固耦合动态计算,得出叶片表面应力及应变量的动态特性,对其进行快速傅里叶变换分析其频域特性,结果显示在转频和24倍转频处有较大幅值的波动,证明导叶叶片数对动应力影响较大。并与实验数据对比,验证计算结果的可靠性,分析其动应力特性的机理,结合工程实际对动态流固耦合模拟计算的实际意义。
[Abstract]:Runner is the core component of hydraulic turbine unit, the safety of runner is directly related to the long-term stable operation of hydropower unit. Although the traditional experimental measurement method has high accuracy and practicability, but the cost is very high. It is necessary to consume a lot of manpower and material resources and time. By using fluid-solid coupling stress simulation technology, the approximate distribution of stress can be obtained to a certain extent at low cost. Based on the starccm finite element analysis software, the computational fluid dynamics simulation analysis of No. 6 unit in the left bank power plant of the three Gorges Project is carried out. The internal and external characteristic parameters of the hydraulic model are obtained and compared with the corresponding experimental data to verify the reliability of the flow field simulation. The fluid-solid coupling numerical simulation technique is used. The stress distribution and strain distribution on the blade surface are obtained by structural simulation analysis of one blade in the impeller, and some nodes on the blade surface are taken to compare with the corresponding experimental data. The reliability of the numerical simulation results is verified, and the shortcomings of the numerical simulation are also properly analyzed. Further, the dynamic characteristics of the blade surface stress and the strain are obtained by the fluid-solid coupling dynamic calculation of the model. The fast Fourier transform (FFT) is used to analyze its frequency domain characteristics. The results show that there is a large amplitude fluctuation at the frequency conversion and 24 times frequency. It is proved that the number of blades has a great influence on the dynamic stress, and compared with the experimental data. The reliability of the calculation results is verified, the mechanism of dynamic stress characteristics is analyzed, and the practical significance of the dynamic fluid-solid coupling simulation calculation combined with the engineering practice is discussed.
【学位授予单位】：华中科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TV734.1

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