【作者】 朱卫国；

【导师】 张仲卿；

【作者基本信息】 广西大学 ， 水工结构， 2004， 硕士

【摘要】 目前，水轮发电机组的容量和尺寸日趋增大，普遍出现在某些工作区域内机组振动过大的现象。这种振动不仅影响机组的自身稳定，也引发厂房建筑物强烈振动，其中最为突出的是大型混流式机组厂房的水力共振。本文初步探讨了水力脉动引起机组乃至厂房结构振动可能性。并以三峡水电站厂房结构振动为例，采用非定常湍流数值模型分析的大涡模拟方法进行了混流式机组的水力振源模拟，并采用频谱分析方法分析振源的频谱特性；分析了厂房结构的自振特性和水力激振载荷作用下的动力响应(谐响应)分析；通过对以上结果的综合考虑得出水电站厂房结构在水力激振载荷作用下的最不利频率段和空间位置。 此文的研究成果，可应用于与三峡机组类型相同的水电站厂房。 文中各章节内容如下： 第一章介绍了厂房振动问题的研究现状和本文研究的主要内容。 第二章介绍了湍流模拟仿真原理，通过不同模拟方法在求解精度、求解消耗和对求解目的适用性等方面的比较，并通过弯管算例论证：大涡模拟(LES)方法是目前计算湍流场中脉动信息的最好方法。 第三章对三峡水电站尾水管进行了三维非定常湍流模拟，并对脉动压力进行频谱分析，得出脉动压力的频率成分和相应的幅值。 第四章对三峡水电站厂房结构进行了精确模态分析，利用尾水管室湍流场模拟的成果分别进行了竖向激振载荷、横向激振载荷作用时在16Hz～40Hz频率段的谐响应分析。更多还原

【Abstract】 Today, the capacity of the water turbo-generator set is larger gradually. The phenomenon of excessive vibration in some load area is founded ubiquitously. This kind of vibration not only affects the reliability of generator unit, but also arouses violence vibration of powerhouse structure, the most outstanding is hydraulic resonance in large-sized Francis turbine. It is discussed elementarily in this paper, that the probability of the fluctuation of waterpower arouses the vibration of generator unit so much as the vibration of powerhouse structure. And the following research is made on the structure vibration of the Three Gorges Hydropower House: Using Large Eddy Simulation method of unsteady turbulent flow numerical analysis to make hydro vibration source simulation for interflow unit of the Three Gorges Hydropower; using frequency spectrum analysis method to analyze the frequency spectrum features; Analyzing structure self-vibration features and dynamic response (harmonic response) under the effect of hydro excitation load. Through comprehensive consideration to above results, we can conclude the worst frequency and space location of the Three Gorges Hydropower house under the effect of hydro excitation load.The research result can be applied on other hydropower house whose turbine-generator set has the same type as Three Gorges Hydropower House’ sThe main contents of this paper are listed as below:In chapter 1, current research situation on hydropower house vibration11and main contents of this paper are introduced.In chapter 2, turbulent simulation theory is introduced. Through comparing different simulation methods on result precision, resolving consumption and result purpose adaptability, After simulated the the curved tube we can say that Large Eddy Simulation(LES) is regarded as the best method at present to simulate the pulsation information in turbulent field.In chapter 3, three dimensions unsteady turbulent flow numerical simulation is used for tail tube of the Three Gorges Hydropower, and frequency spectrum analysis is made for pulsation pressure, therefore frequency and corresponding amplitude of pulsation pressure is concluded.In chapter 4, precise modal analysis is carried out for the Three Gorges Hydropower House structure. By using the result from turbulent field simulation in tail tube chamber, harmonic response analysis are carried out respectively on vertical excitation load , transverse excitation load in 16Hz~40Hz frequency sect.更多还原