为深入研究S形轴伸贯流泵装置过流部件的水力性能,采用CFD技术对泵装置进行了多工况全流道的数值计算,分析了泵装置各过流部件的水力性能,重点阐述了3种特征工况(小流量工况KQ=0.368、最优工况KQ=0.490、大流量工况KQ=0.613)时转轮叶片表面的静压分布、摩擦力线、各轴向弦长位置的轴向速度分布以及导叶体内部流态和回收环量效果。结果表明:在轮缘侧的叶片压力面静压值较大,在轮毂侧的叶片吸力面的静压值较大,轮缘侧较小,且随着展向位置Span值的增大,压力面与吸力面的压差呈现出逐渐递增趋势。在最优工况时,从导叶体进口至出口,导叶体的静压值逐渐增大。随流量的减小,导叶体的回收环量比CH先减小后增大。在最优工况KQ=0.490时,回收环量比CH最小,其值仅为0.031。针对该泵装置进行了同尺寸的物理模型试验,获得了泵装置的综合特性曲线,在叶片安放角-2°时,新型S形轴伸贯流泵装置的最高效率达83.55%,此时流量系数KQ=0.443,扬程系数KH=0.828。通过物理模型试验结果对泵装置外特性预测结果进行了验证,对比分析结果表明数值模拟是可信的。
In order to further study the hydraulic performance of flow passage components for S –shaped shaft extension tubular pumping system, the whole flow passage of pumping system were simulated based on the CFD technology under multiple operating conditions. The inner flow pattern and hydraulic performance of flow passage components were analyzed. Focusing on details of flow field, the flow characteristics in the impeller and guide vane were analyzed under three different operating conditions (the small flow rate condition KQ=0.368, the best efficiency condition KQ=0.490 and the large flow rate condition KQ=0.613). The static pressure of pressure surface near shroud is larger, and the static pressure of suction surface near hub is larger than that near shroud. With the increase of spanwise location value, the differential pressure between pressure surface and suction surface increases gradually. The static pressure of guide vane surface increases from inlet section to outlet section at KQ=0.490. With the decrease of flow, the recycling circulation ratio CH decreases firstly then increases, and the minimum ratio CH was 0.031 at KQ=0.490. The accuracy and effectiveness of numerical results were verified by the physical model test. The test results show that when the flow coefficient KQ=0.443 and the head coefficient KH=0.828, the highest efficiency of pumping system is 83.55% at the blade angle -2°.