基于CFD的水电站厂房水力振源模拟研究

Study on Hydraulic Source and It’s Effect of Powerhouse Vibration Based on CFD

传统的水力振源特性研究主要依赖于模型试验,计算方法亦过于简化。通过建立水轮机全流道模型,基于CFD计算软件,对正常工况下的厂房进行了流体计算,总结了蜗壳壁面压力脉动的变化、分布规律及数值大小,进而根据CFD计算结果拟定了5种水力振源施加方案,并利用谐响应算法计算了厂房楼板、机墩、风罩等薄弱部位的振动响应情况,认为可根据流体计算结果在蜗壳内壁不同部位施加相应简谐荷载;且在流体计算结果中提取厂房蜗壳壁面各点的压力脉动数值,采用时程分析法施加于蜗壳对应节点,观察厂房结构振动响应情况,给出了水电站厂房水力振源更加精确、合理的模拟与施加方式。

The traditional research of hydraulic vibration source characteristics mainly depends on the model test,and the calculation method is too simple.Based on the CFD software,the whole flow channel model of water turbine was established to calculate the flow field of powerhouse under normal working condition.The change rule of the volute wall pressure fluctuation was analyzed.According to the CFD calculation results,five kinds of hydraulic vibration source schemes were set up.The harmonic response algorithm was used to calculate the vibration response of weak positions,such as powerhouse floor,turbine pier,fan housing.Based on the calculation results,the corresponding harmonic load can be exerted on the inner wall of the volute.The pressure fluctuation of the volute can be extracted from the fluid calculation results.The time-history method was used to monitor the vibration response of powerhouse structure.So,hydraulic vibration source of powerhouse can be simulated accurately.