叶轮流速系数对泵正反转性能参数比的影响

为研究叶轮流速系数对离心泵反转作液力透平(PAT)泵工况和透平工况水力性能参数比的影响，采用renormalization group(RNG) k-ε湍流模型，通过计算流体动力学软件CFX计算了比转速为23~225的20个PAT叶轮单流道模型的流速系数，揭示了泵工况和透平工况流速系数的分布规律，建立了考虑流速系数的PAT泵工况与透平工况扬程比和流量比。结果表明:PAT透平工况叶轮流速系数大于泵工况。通过对不同比转速的6台工业PAT的外特性实验表明:与Stepanoff等提出的方法相比，考虑流速系数时PAT水力性能参数比与实验结果最为接近，其扬程比平均误差为5.38%，流量比平均误差为5.16%。该成果为PAT的选型设计和性能预测提供理论支撑。 

Effect of impeller velocity coefficient on parameters ratios between pump and its reverse mode

In order to study the head ratio and flow rate ratio between pump and turbine mode of pump as turbine (PAT) based on the impeller velocity coefficient, 20 single passage impellers with specific speed 23-225 were analyzed based on renormalization group (RNG) k-ε simulation by CFX. The distribution of velocity coefficient was revealed for pump mode and turbine mode, and new head ratio and flow rate ratio between pump and turbine mode based on impeller velocity coefficient were proposed. Results showed that the impeller velocity coefficient of turbine mode was higher than the pump mode. Then 6 industrial PATs were experimented in experiment rig, indicating the result by the this method had less error than the results of Stepanoff, et al. The average errors of head ratio and flow rate ratio were just 5.38% and 5.16%, respectively. The study provides a theoretical basis for the selection and performance prediction of PAT.