单流道泵内部非定常流动特性

UNSTEADY FLOW CHARACTERISTIC WITHIN SINGLE CHANNEL PUMP

将叶片和蜗室作为一个整体,对单流道泵内部三维非定常流动特性进行研究,经分析提出了单流道泵内部三维非定常势流流动和三维非定常湍流流动的数值模拟方法,分别计算了单流道泵内部的速度场、压力场和叶片表面的压力分布,对进一步研究单流道泵内部流动具有重要意义。在此基础上计算了叶轮所受的径向力及其变化趋势,为提高单流道泵运行稳定性提供了理论依据。此外还计算了扬程、平均水功率和效率,并与试验值作对比。尽管忽略粘性使得势流计算得到的速度场在蜗壳的局部区域出现反方向流动,从而导致叶片压力面压力沿展向波动变化,但其性能曲线与试验值变化趋势一致,粘性计算结果与试验值相比,精度较高。

The impeller and the volute are viewed as a whole calculation field, 3-D unsteady flow characteristic within single channel pump is studied. By analyzing, numerical simulation methods of 3-D unsteady potential flow and turbulent flow within the pump are presented. Above two methods are adopted to calculate single channel pump＇s internal velocity field, pressure field and blade surface pressure distribution respectively, which would be significant for further studying pump＇s internal flow. Based on these, radial force of impeller and its variation tendency in different operating conditions are solved, which provide theory gist for enhancing the stability of the pump during the running. On the same time, head, the average water-horse power and efficiency are calculated and compared with the experimental data. The velocity field calculated by potential flow method has reverse-direction flow in partial area of volute chamber, which causes fluctuant pressure on blade pressure surface, but the tendency of performance curves are correspondence with experimental data. Accuracy of viscous solution is better.