Numerical study of vortex rope during load rejection of a prototype pump-turbine
Numerical study of vortex rope during load rejection of a prototype pump-turbine
复制标题
DOI：
10.1088/1755-1315/15/3/032044
复制
发表时间：
2012-11
期刊：
影响因子：
--
通讯作者：
J. Liu;S. Liu;Y. K. Sun;Y. Wu;L. Q. Wang
中科院分区：
文献类型：
--
作者：
J. Liu;S. Liu;Y. K. Sun;Y. Wu;L. Q. Wang
采用动网格法（DM）和网格重划法对某水泵水轮机原型机组甩负荷过程进行了三维非定常数值模拟和定常数值计算。采用流体耦合法对转轮转速进行了预测。基于湍流模型进行了瞬态计算和稳态计算。结果表明，稳态计算结果对瞬态过程外特性的预测误差较大。在过渡过程中，飞逸转速可达到初始转速的1.15倍。涡带出现在水泵水轮机运行到零力矩点之前。涡绳与转轮的旋转方向相同。随着流量的减小，涡带分为两部分。在整个瞬态过程中，压力水平不断下降，并与实验结果进行了对比和验证。该计算方法可用于暂态过程的故障诊断和暂态过程的优化。
A transient process of load rejection of a prototype pump-turbine was studied by three dimensional, unsteady simulations, as well as steady calculations.Dynamic mesh (DM) method and remeshing method were used to simulate the rotation of guide vanes and runner. The rotational speed of the runner was predicted by fluid couplingmethod. Both the transient calculation and steady calculation were performed based on turbulence model. Results show that steady calculation results have large error in the prediction of the external characteristics of the transient process. The runaway speed can reach 1.15 times the initial rotational speed during the transient process. The vortex rope occurs before the pump-turbine runs at zero moment point. Vortex rope has the same rotating direction with the runner. The vortex rope is separated into two parts as the flow rate decreases to 0. Pressure level decreases during the whole transient process.The transient simulation result were also compared and verified by experimental results. This computational method could be used in the fault diagnosis of transient operation, as well as the optimization of a transient process.