水泵水轮机空化流及转轮轴向受力分析

ANALYSIS ON CAVITATING FLOW AND AXIAL FORCE IN PUMP-TURBINE

为研究水泵水轮机在水泵工况运行时的空化特性及转轮所受轴向力的变化情况,以某抽水蓄能电站模型水泵水轮机模型为研究对象,基于Zwart空化模型和SST k-ω湍流模型,在不同流量系数下进行不同空化数的三维数值模拟并与实验对比验证。结果表明:在小流量和设计流量工况下气泡首先出现在吸力面靠近前缘位置并逐步向叶片出口和压力面扩展,而在大流量工况下气泡首先在压力面出现,并扩展至吸力面区域且已远离前缘位置,同时探讨了轴向力随着空化数的变化规律。

In order to obtain the cavitation performance and axial force of pump-turbine in pump mode,a pump-turbine model in a pumped storage power station was selected as the study object. based on SST k-? turbulence model and Zwart cavitation model,the numerical simulation is carried in different flow coefficient and compared with the experiment results.Results show that:with the decrease of the total pressure in draft inlet,vapors generated at suction surface of blade near the leading edge at first and then extend to the exit of runne and pressure surface of blade under low flow rates and design flow rates. However,under the condition of large flow,vapors generated at pressure surface of blade near the leading edge at first and then extend to the exit of runner and suction surface of blade leading edge away from the leading edge.Meanwhile the change rule of axial force with cavitation number under different flow conditions is discussed.