叶轮出口环量非线性分布条件下混流泵性能研究

为研究反问题设计中叶轮出口翼展方向环量非线性分布对混流泵外特性及内流场的影响，拓展混流泵优化设计空间，在试验验证数值模拟准确性的基础上，通过在叶轮出口翼展方向插入5个控制点控制环量分布的方法构建了17种不同环量分布形式；在其他设计参数不变的基础上使用反问题设计方法对其进行三维造型并使用商业软件CFX进行数值模拟，对其外特性及内部流场进行对比分析。结果表明：环量分布形式对设计工况与小流量工况叶轮效率影响较小，对大流量工况叶轮效率影响较大；在全工况范围内，环量分布形式对叶轮空化性能影响均较大；环量分布形式可显著改变叶轮内部流场，影响叶片不同叶高处的做功能力。

Performance of Mixed Flow Pump under Condition of Non-linear Distribution of Impeller Exit Circulation

In order to study the influence of impeller outlet span-wise circulation nonlinear distribution on external characteristics and internal flow field of the mixed flow pump in the inverse design, expand the optimization space, on the basis of the accuracy of numerical simulation verified by experiments, totally 17 different circulation distribution forms were constructed by inserting five control points into the span-wise of impeller exit to control the circulation distribution. Keeping other design parameters unchanged, the inverse design method was used to carry out three-dimensional modeling, and simulation calculation was carried out by commercial software CFX, the external characteristics and inner flow field were compared and analyzed. The results showed that the circulation distribution form had less influence of impeller efficiency on design points and small flow points. When the circulation value was small at the shroud and large at the 0.75ra, the pump efficiency under the condition of large flow would be greatly improved. In addition, compared with the circulation at the shroud, the circulation at 0.75ra played a leading role in improving the pump efficiency under the condition of large flow. The circulation distribution form had a greater impact on the cavitation performance of the impeller under every flow condition. The cavitation performance under small flow conditions and design flow conditions can be effectively improved when the circulation value was bigger at shroud and small at 0.75ra, but the cavitation performance under large flow conditions would be decreased accordingly. The circulation distribution form can significantly change the internal flow field of the impeller and affect the work capacity of the blade at different blade heights. Therefore, to further improve the comprehensive performance of mixed flow pump when using inverse design method, researching the nonlinear distribution of impeller outlet circulation had an important significance.