中文摘要：

基于细泡状流动假设,采用双流体模型对一叶片式混输泵叶轮内的气液两相流动进行定常和非定常数值模拟。计算中,进口含气率为15%,湍流模型采用基于k-ω模型的SST模型,相间作用力考虑了阻力和附加质量力。通过分析流域的含气率及两相速度矢量分布,探讨了混输泵内气液两相非定常流动特性。结果显示,混输泵叶轮内的两相输运过程出现＂不连续气团运动＂现象。该现象的形成与气泡尺寸及气体所受的相间作用力有关,并且只有在非定常计算中才能得到清晰展现。计算还发现,气相轴面涡的位置与高含气率区几乎完全对应,说明气相旋涡是造成气体局部聚集的主要因素之一。通过对比外特性计算和实验结果,验证了所用数值模型和方法的可靠性。

英文摘要：

Based on the assumption of tiny bubbly flow, the gas-liquid two-phase flow in a multiphase rotodynamic pump was numerically simulated with two-fluid model in both steady and unsteady modes. In the simulation, the inlet gas volume fraction was 15%. The κ-ω based SST model was used for turbulence. The drag force and the added mass force were accounted for in the interracial momentum transfer terms. Through the analyses of the distribution of gas volume fraction and velocity vectors, the unsteady flow characteristic in the multiphase pump was explored. The results demonstrated that a phenomenon named ＂discontinuous air mass movement＂ would occur in the two-phase transport process. The formation of this phenomenon was related to the bubble size and the interracial forces acting on the gas, and only in unsteady simulation could this phenomenon be observed. Also, it was found that the locations of gas vortexes in meridional plane were almost fully corresponding to the regions of high gas volume fraction, which illustrated that gas vortex was one of the main factors that led to gas accumulation. In addition, through comparison of the external characteristics between the simulation and the experiment, the reliability of the numerical method was validated.