出口环量分布对泵诱导轮性能的影响

为减少对经验参数的依赖性，在诱导轮设计过程中引入出口环量分布规律来控制叶片不同叶高处安放角，根据3种不同函数表达式的出口环量分布，设计了3种不同类型的诱导轮，并通过数值计算的方法，研究了出口环量分布对诱导轮性能的影响.水力设计结果表明：出口环量分布规律可作为诱导轮设计的控制参数，它直接影响诱导轮的包角大小和叶片长度.数值计算结果表明：减小轮毂侧环量，增大轮缘侧环量，可防止叶片轮毂因安放角过大而扭曲严重，进而提高叶片水力效率；同等流量下，二次递增型诱导轮扬程最高，有利于提高离心轮的抗汽蚀性能；二次递增型诱导轮综合性能最好，而线性递增型诱导轮综合性能最差；水平型诱导轮内部流场最稳定，但进口轮缘处有较强旋涡产生.因此，在诱导轮设计过程中，选用二次递增型出口环量分布较为合理.

Influence of outlet circulation distribution on hydraulic characteristics of pump inducer

In order to reduce dependence on empirical parameters during inducer design, in this paper different outlet circulation distributions are introduced to regulate blade angle across blade height. Three inducers with different outlet circulation distributions were designed, and their influence on the inducer performance was studied by numerical calculation. Hydraulic design results show that the circulation distribution can be used as a control variable in inducer design and affects both wrap angle and length of inducer blades directly. The numerical simulation results illustrate that decreasing the circulation near the hub and increasing the circulation near the blade tip can prevent inducer blade angle at the hub from being twisted seriously and improve blade hydraulic efficiency. At the same flow rate, the inducer with quadratic increasing circulation distribution has the highest head which can enhance the centrifugal impellers capability of anti cavitation. The comprehensive performance of the inducer with quadratic increasing circulation distribution is the best, while the performance of that with linear increasing circulation distribution is the poorest. The flow field of the inducer with constant circulation distribution is the most stable, but a strong vortex is present near the inlet tip. Accordingly, it is more proper to select the quadratic increasing circulation distribution in inducer hydraulic design.