径向叶片式超小型泵内部流动分析及设计优化

发布时间：2018-01-09 12:07

本文关键词：径向叶片式超小型泵内部流动分析及设计优化　出处：《清华大学》2011年硕士论文　论文类型：学位论文

【摘要】：随着人类社会的发展与技术的进步，超小型泵在各个领域都得到了广泛的应用。本文对具有径向叶片式开式叶轮的超小型泵进行了研究，为未来超小型泵的应用拓展奠定基础。本文通过性能试验、PIV试验及数值计算的方法考察了径向叶片和弯曲叶片叶轮的超小型泵外特性和内部流动情况，得到如下结论：1）通过对比发现轴面流道相同的径向叶片式超小型泵的扬程高于弯曲叶片式超小型泵，而效率略低于弯曲叶片式超小型泵；在大流量工况时，径向叶片式超小型泵表现出比弯曲叶片式超小型泵更好的能量特性。因此，从总体的水力特性看，径向叶片式超小型泵具有不逊于弯曲叶片超小型泵的水力性能，并且能在较大范围内保持较高的水力效率。2）弯曲叶片式超小型泵的压力从进口到出口均匀增加，但径向叶片式超小型泵的压力在流道中段压力增加较小，但在叶片后半段压力迅速增加。从叶片压力面与吸力面的压力差来看，弯曲叶片沿叶片长度方向上压力差变化不大，但径向叶片式超小型泵在叶片进口和出口处的压力差较大，而在叶片中段压力差较小。3）PIV实验和数值计算的结果均表明径向叶片式超小型泵叶轮内流动具有较强的非均匀性，在叶片出口附近产生了漩涡、回流等现象。虽然径向叶片式超小型泵的流动均匀性不如弯曲叶片式超小型泵，但泵流道内的湍动能较大，有利于提高叶轮的做功能力。4）实验和数值计算均表明吸入管和蜗壳的结构对超小型泵的水力性能和内部流动有明显的影响。本文通过数值模拟的方法，研究了叶尖间隙、叶轮轴面流道形状、长短叶片等因素对径向叶片式超小型泵水力性能的影响。计算结果表明，径向叶片式超小型泵的水力性能受叶尖间隙的影响主要表现在扬程系数略有下降、出口速度分布发生一定变化，等；过流面积单调增加的叶轮在最优工况处具有较高的效率和扬程，但最优工况点的流量较小。此外，计算结果表明叶片进口的过流面积对超小型泵的水力性能有明显的影响；长短叶片设计对超小型泵的水力性能影响不大，，但对进口处的流动情况有明显的影响。
[Abstract]:With the development of human society and the progress of technology, the subminiature pump has been widely used in various fields. In this paper, the ultra-small pump with radial vane open impeller has been studied. It lays a foundation for the application and expansion of subminiature pumps in the future. In this paper, the external characteristics and internal flow of the radial and curved blade impellers are investigated by PIV test and numerical calculation. The conclusions are as follows: (1) by comparison, it is found that the head of radial vane type subminiature pump with the same axial flow channel is higher than that of curved vane type superminiature pump, but the efficiency is slightly lower than that of curved vane type superminiature pump; In the case of large flow rate, radial vane subminiature pump has better energy characteristics than curved vane subminiature pump. Therefore, from the view of overall hydraulic characteristics. The radial vane type superminiature pump has no inferior hydraulic performance than the curved vane superminiature pump. And it can keep higher hydraulic efficiency in a large range. 2) the pressure of the curved vane type subminiature pump increases evenly from the inlet to the outlet, but the pressure of the radial vane type subminiature pump increases slightly in the middle section of the flow channel. But the pressure increased rapidly in the latter half of the blade. From the pressure difference between the blade pressure surface and the suction surface, the pressure difference of the curved blade along the blade length changed little. But the pressure difference between the inlet and outlet of the radial vane pump is large. The results of PIV experiment and numerical calculation show that the flow in the impeller of radial vane type subminiature pump has strong inhomogeneity and there is a swirl near the blade outlet. Although the flow uniformity of radial vane subminiature pump is not as good as that of curved vane pump, the turbulent kinetic energy in the flow channel of the pump is larger. The experimental results and numerical calculations show that the structure of suction tube and volute has a significant effect on the hydraulic performance and internal flow of the subminiature pump. In this paper, the effects of the tip clearance, the shape of the blade shaft surface and the long and short blade on the hydraulic performance of the radial vane type subminiature pump are studied by means of numerical simulation. The hydraulic performance of radial vane type subminiature pump is mainly affected by the tip clearance in that the lift coefficient decreases slightly and the outlet velocity distribution changes to a certain extent. The impeller with monotonous increase of over-flow area has higher efficiency and head at the optimum working condition, but the flow rate at the optimal working condition is smaller. The results show that the flow area at the inlet of the blade has an obvious effect on the hydraulic performance of the subminiature pump. The design of long and short blades has little effect on the hydraulic performance of the subminiature pump, but has obvious influence on the flow situation at the inlet.
【学位授予单位】：清华大学
【学位级别】：硕士
【学位授予年份】：2011
【分类号】：TH38

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