微型旋涡泵水力特性与轴向力计算

对新结构闭式叶轮旋涡泵进行数值模拟,采用RANS湍流模型求解三维不可压缩问题,计算了旋涡泵的水力特性,分析了旋涡泵工作时叶轮与泵壳间隙处油膜对叶轮的轴向承载机理,并进一步讨论了叶轮两侧的楔形槽对油膜承载能力的影响.结果表明：旋涡泵的水力特性与试验数据趋势吻合,数值相近,验证了仿真计算的可靠性.轴向力分析显示,旋涡泵工作时浮动叶轮的轴向支撑由在叶轮两侧形成的油膜实现,油膜因厚度不同,造成径向的压力降不同,油膜较薄则泄压慢,油膜较厚则压力更均匀,叶轮上下表面受力不等而产生支撑力,而楔形结构能够产生附加的支撑力,强化了支撑效果.研究结果对旋涡泵的设计和研究提供参考依据.

Hydraulic characteristics and axial force of micro vortex pumps

Numerical simulation of a new shrouded impeller vortex pump was carried out. The method of solving steady three-dimensional incompressible continuity equation and RANS equations were employed to calculate the hydraulic performance of the vortex pump. The axial bearing mechanism of the oil film toward the impeller was analyzed, and further discussion about the influence of the wedge shaped groove on both sides of the impeller on the bearing capacity of the oil film was made. It was found that the predicted hydraulic property was consistent with test data, which proves the calculating model reliable. In addition, the results show that the axial supporting of floating impeller is rely on the oil film formed on both side of the impeller. The different thickness of oil fihn results in different radial pressure drops. The thinner one results in the slow pressure drop while the thicker one results in the unitorm pressure, which causes an unequal force on impeller and provides the holding power. Moreover, the wedge shaped structure enhances the supporting effect. The study is useful for the design and analysis of vortex pumps.