The tip clearance induces the tip leakage vortex (TLV), which has a great impact on the pressure fluctuation characteristics of the multiphase pump. To investigate the effect of the tip clearance on the pressure fluctuations, based on the Reynolds time-averaged Navier-Stokes equation and the shear stress transfer (SST) k - ω turbulence model, the three-dimensional turbulent flow in the pump is numerically simulated for different tip clearances in the water and gas-liquid two-phase cases by using the ANSYS CFX software and the results are verified with experimental data. It is shown the greater pressure fluctuation intensity corresponds with the TLV both in the water and gas-liquid two-phase cases. In the meantime, the location of the maximum pressure fluctuation intensity is related to the tip clearance size. In addition, for different tip clearances, the pressure fluctuation intensity with the rotor and stator interaction (RSI) is relatively larger. The difference is that when R_tc = 1.5 mm , the pressure fluctuation intensity near the impeller middle point is also relatively larger. On the whole, the pressure fluctuation intensity in the gas-liquid two-phase case is larger than that in the water case. Furthermore, the gas causes the frequency of the high-amplitude pressure fluctuation in the impeller and the diffuser to be shifted from 7 f_n (f_n denotes impeller rotational frequency) and 3 f_n to the low-frequency region, respectively. The pressure fluctuations at the blade-passing frequency (BPF) and the multiple BPFs gradually disappear. Meanwhile, the amplitude at the dominant frequency in the gas-liquid two-phase case is at least one order of magnitude smaller than that in the water case, and the peak-to-peak value of the pressure fluctuation is also much smaller.

叶尖间隙引起叶尖泄漏涡（TLV），对多相泵的压力脉动特性影响很大。为了研究叶尖间隙对压力波动的影响，基于雷诺时间平均 Navier-Stokes 方程和剪切应力传递 (SST) k - ω湍流模型，利用ANSYS CFX软件对水和气液两相情况下不同叶尖间隙的泵内三维湍流进行数值模拟，并用实验数据验证了结果。结果表明，在水和气液两相情况下，较大的压力波动强度与TLV相对应。同时，最大压力波动强度的位置与叶尖间隙大小有关。此外，对于不同的叶尖间隙，与转子和定子相互作用（RSI）的压力波动强度相对较大。不同的是，当R _tc= 1.5 mm ，叶轮中点附近的压力波动强度也相对较大。总体而言，气液两相情况下的压力波动强度大于水情况下的压力波动强度。此外，气体使叶轮和扩压器中的高振幅压力波动的频率从7 f _n ( f _n表示叶轮旋转频率)和3 f _n偏移。分别到低频区。叶片通过频率（BPF）和多个BPF处的压力波动逐渐消失。同时，气液两相情况下主频处的幅值比水情况下至少小一个数量级，压力波动的峰峰值也小得多。