入口非均匀流对轴流泵性能和压力脉动的影响

为研究入流条件对轴流泵的影响,建立了2种不同类型的非均匀速度入口分布,分别与均匀入流进行比较,得到非均匀入口边界条件对轴流泵影响的数值计算结果.将均匀入流下的数值模拟结果与试验值进行对比,验证了数值模型的可信性.在0.7Q~1.2Q工况范围内,对轴流泵的扬程、效率和径向力等曲线进行了对比分析,得出受入口速度非均匀性影响、轴流泵性能和径向载荷的变化结果.最后,在定常模拟的基础上,对设计工况下叶轮入口、叶轮出口和导叶出口处的压力脉动进行了监测,得到了2种非均匀入流条件对轴流泵3个典型位置处压力脉动的影响情况.结果表明,通过控制进口入流情况,可以使文中所研究的轴流泵的水动力性能好于轴向均匀入流时的水动力性能.

Effects of non-uniform suction pressure fluctuation in flow on performance and axial-flow pumps

To study the effect of inflow conditions on an axial flow pump, two different types of non-uniform inlet velocity distributions were established. By comparing with uniform inflow conditions, the effects of the non-uniform inflow conditions on pump performance, radial forces and pressure fluctuations were achieved by numerical simulations. Comparison of numerical simulation results and experimental values under uniform inflow verifies the accuracy of the numerical model. A comparative analysis of the effects on pump head, efficiency and radial force curves was performed under 0.7Q - 1.2Q conditions. The variation of the axial flow pump performance and radial loads with the non-uniformity of the inlet velocity was obtained. Finally, based on the unsteady simulation, pressure fluctuations at impeller inlet, impeller outlet and guide vane exit at design condition were monitored, and the effects of two non-uniform inflows on pressure pulsations at three typical positions were achieved. The results show that by controlling the inflow situation, the hydrodynamic performance with non-uniform inflow is better than that with uniform inflow distribution.