摘要
在模型水泵水轮机空化两相流动模拟研究中,通常不考虑水流压缩性对压力脉动的影响,但在原型水泵水轮机过渡过程计算中,该影响显著。因此,提出了一种可压缩的空化两相流动模拟方法来同时考虑液态水和气液两相中间混合物介质的压缩性。在该模拟方法中,结合液态水的弱可压缩模型和气液两相中间介质的状态方程得到了依据流场压力分布对流体密度进行修正的计算模型。采用该密度修正模型对一个原型水泵水轮机的甩负荷过程进行了模拟,研究首次在机组甩负荷过程转轮高压进口回流涡中捕捉到了空化现象。此外,研究发现,空化和转轮进口回流涡的耦合作用诱发空载工况附近出现了低于5倍额定转频的高幅值压力脉动。
In the simulation study of cavitation two-phase flow in a model pump turbine,the influence of water flow compressibility on pressure pulsation is usually not considered,but in the calculation of the transition process of the prototype pump turbine,this influence is significant.Therefore,a compressible simulation method for cavitation two-phase flow was proposed to simultaneously consider the compressibility of the mixture medium between liquid water and gas-liquid two-phase.In this simulation method,a computational model was obtained by combining the weakly compressible model of liquid water and the state equation of gas-liquid two-phase intermediate medium,which corrected the fluid density based on the pressure distribution of the flow field.The density correction model was used to simulate the load rejection process of a prototype pump turbine,and the cavitation phenomenon was first captured in the high-pressure inlet return vortex of the turbine during the load rejection process of the unit.In addition,research has found that the coupling effect of cavitation and inflow vortex at the impeller inlet induces high amplitude pressure pulsation below 5 times the rated rotational frequency near the no-load condition.
作者
付晓龙
李德友
王洪杰
魏显著
FU Xiaolong;LI Deyou;WANG Hongjie;Wei Xianzhu(School of Energy Science and Engineering,Harbin Institute of Technology,Harbin,Heilongjiang 150001,China;Harbin Institute of Large Electrical Machinery,Harbin,Heilongjiang 150040,China)
出处
《自动化应用》
2024年第4期176-179,共4页
Automation Application
基金
国家自然科学基金项目(52209108,52079034)
四川省科技计划项目(2023YFQ0021)
黑龙江省自然科学基金联合引导项目(LH2023E058)。
关键词
原型水泵水轮机
空化两相流
压缩性
压力脉动
回流涡空化
prototype pump turbine
two-phase cavitation flow
compressibility
pressure pulsation
backflow vorticity cavitation
