【摘要】 为研究水泵水轮机的空化性能,文章采用基于SST k-ω湍流模型和Zwart空化模型的两相流计算方法,对某抽水蓄能电站的模型水泵水轮机进行定常计算,并将计算结果与试验结果进行了对比。对不同导叶开度下3个非设计工况的数值计算结果进行了对比分析,结果表明:随着流量增大,涡带形状有所不同,小流量工况下涡带形状较为复杂,中流量工况下涡带为螺旋形,大流量工况下涡带为柱状;涡带半径越来越小,涡带中心的压力越来越低,当涡带内部压力低于汽化压力时,就会产生空腔空蚀,反而使得效率下降。当转轮出口处外侧存在圆周速度分量,中心区域速度较小时,会形成涡带,交界区域速度急剧变化的位置与涡带半径相对应,涡带形状与速度分布情况有关。更多还原

【Abstract】 In order to investigate the cavitation performance of the pump turbine,the flow in a model turbine of a pumped storage power station was simulated based on SST k-ω turbulence model and Zwart cavitation model.The simulation results and experiment data were compared.Three non-design conditions under different guide vane opening degrees were simulated and the results showed that:as the flow rate increases,the structure of the vortex rope changed.The structure of the vortex rope is relatively complex under low flow conditions,while it is spiral under medium flow conditions and columnar under large flow conditions.The radius of the vortex rope and the pressure inside the vortex rope decreases.When the pressure of the vortex rope core is lower than the vaporization pressure,cavitation occurs and the efficiency reduces.The vortex rope will be formed when there are circumferential velocity component in the runner outlet and a small center region velocity.The position where the velocity of the boundary region changes rapidly is related to the radius of the vortex rope,and the velocity distribution is connected with the shape of the vortex rope.更多还原