The unsteady flow and fluid exciting force inside the multistage centrifugal pump were analyzed on the basis of large eddy simulation (LES). The reliability of the numerical simulation was verified by the experimental performance. The performance of pump calculated was closer to the experimental one than that by the Reynolds time average turbulence model, and the errors were 0.36% and 1.14% at the design flow rate, respectively. The results showed that the different distribution and magnitude of the inlet velocity at each stage impeller contributed to the difference of the head for each one. With the increase of flow rates from 0.4Q to 1.2Q, the rule of axial forces for each stage was roughly the same but the total axial force increased from 25.02kN to 29.92kN. The radial force in the Z direction was smaller than the one in the Y direction, and the amplitude of the main frequency in the Z direction changed more gently for the double tongue. Adopting back-to-back impeller distributions can effectively reduce the axial force. The symmetric distributed double tongue can reduce the radial force and play a key role in reducing the vibration of the centrifugal pump.

基于大涡模拟(LES)分析了多级离心泵内部的非定常流动和流体激振力。通过实验性能验证了数值模拟的可靠性。与雷诺时间平均湍流模型相比，计算的泵性能更接近实验性能，在设计流量下误差分别为0.36%和1.14%。结果表明，各级叶轮入口速度的不同分布和大小导致了每一级叶轮的扬程差异。随着流量从0.4Q增加到1.2Q，各阶段轴向力的规律大致相同，但总轴向力从25.02kN增加到29.92kN。Z方向的径向力小于Y方向的径向力，双舌的Z方向主频振幅变化更平缓。采用背靠背叶轮分布可有效降低轴向力。对称分布的双舌片可减小径向力，对降低离心泵的振动起到关键作用。