基于比例因子的离心泵圆弧叶片造型研究

Research on shape construction of circular blade in centrifugal pump based on scale factor method

针对中低比转速离心泵，提出了能够统一各种圆弧叶片造型方法的比例因子法，推导了叶型参数的计算公式，分析了比例因子对叶片安放角、叶片长度等的影响，并采用数值模拟方法对不同比例因子下的泵内流场进行了性能预测。结果表明，不同比例因子下的叶型参数、流动参数及性能参数变化范围很大。比例因子较小时，节流损失较大，泵扬程较低；比例因子较大时，脱流损失较大，泵效率较低，存在较优的比例因子区间[0．15，0．35]，使叶片安放角平滑变化，泵的综合性能较优，对应的曲率半径比为1．4～1．9。采用Pfleiderer方法及本文的角度平均法获得的叶片安放角变化较为平稳，可用于离心泵的初步设计。

A scale factor method is put forward, which can unify the different construction methods of circular blade for low-specific-speed centrifugal pumps （LSPCPs）. A general formula to calculate the parameters of blade profile is deduced. The blade angle and length vs. scale factor are analyzed. The performances of flow field in a LSPCPs at different scale factors are predicted with numerical simulation method. The results indicate that the parameters of blade profile, flow and performance of LSPCP change in a wide range at different scale factors, the throttling loss increases and pump lift decreases when the scale factor decreases; the off-flow loss increases, efficiency of pumps decreases and the better scale factor intervals 0.15 and 0.35 exists when the scale factor increases, which may make the blade setting angle smooth and the combination property better. The ratio of corresponding curvaRtre radius is 1.4-1.9. The blade setting angle obtained by Pfleiderer method and the angle-average method has smooth change. Therefore, the method can be used in the initial design of centrifugal pump.