叶片式气液混输泵全流道内流场特性分析  

Flow Characteristics Analysis for the Whole Flow Passage of a Multiphase Rotodynamic Pump

作　　者：张文武 余志毅[1] 李泳江 程学良 ZHANG Wenwu;YU Zhiyi;LI Yongjiang;CHENG Xueliang(School of Mechanical Engineering,Beijing Institute of Technology,Beijing 100081)

机构地区：[1]北京理工大学机械与车辆学院

出　　处：《机械工程学报》2019年第10期168-174,共7页Journal of Mechanical Engineering

基　　金：国家自然科学基金(51579006);北京理工大学基础研究基金(20150342012)资助项目

摘　　要：有关叶片式气液混输泵全流道内流场特性的研究还不充分,因此选取空气-水作为输运介质,基于ANSYS_CFX对一叶片式气液混输泵进行全流道数值模拟。计算域采用ICEM_CFD和TurboGrid进行了结构化网格划分。通过数值计算获取的外特性数据与试验数据进行对比,数值计算方法的可靠性得到了验证。计算结果显示,不同进口含气率下叶轮流道内的气体主要聚集在叶轮出口轮毂处的吸力面附近且随着进口含气率的增加,气体在该处的聚集程度增强,分布的不均匀度增加。9%、15%和21%进口含气率下叶轮内流体的最大湍动能分别是3%进口含气率下的1.07倍、1.53倍和1.83倍。不同进口含气率下导叶内的气体均在轮毂处聚集,且沿着流动方向,轮毂处的气体逐渐向主流区扩散。9%进口含气率下,叶轮内气体的聚集程度随着流量的增加逐渐减小,而导叶内的气体在设计流量(Qd)时聚集程度最大,大流量(1.25Qd)次之,小流量(0.75Qd)最小。以上研究结果更深入地揭示了叶片式气液混输泵的内流场特性,可以为该类泵的优化设计提供参考,提高其输运效率。Research on the flow characteristics for the whole flow passage of a multiphase rotodynamic pump is insufficient.Therefore, based on ANSYS_CFX, simulations are performed for the flow in such a pump with the medium of air-water. Structured grids for the computational domain are generated using ICEM_CFD and TurboGrid. The reliability of simulation is verified by comparing with the experimental data. The results show that, under different inlet gas void fraction(IGVF) conditions, the gas in the impeller mainly accumulated at the impeller hub and the closer to the impeller outlet and the blade suction surface, the higher degree for gas aggregation. With the increase of IGVF, the degree of gas aggregation in the impeller, as well as the gas inhomogeneity, is higher. The maximum value of the turbulence kinetic energy at IGVF=9%, 15% and 21% are respectively 1.07, 1.53 and 1.83 times than that at IGVF=3%. Meanwhile, the gas in the diffuser mainly accumulated near the hub and gradually spread toward the mainstream region along the flow direction. For IGVF=9%, the degree of gas aggregation in the impeller decreased gradually with the increase of flow rate, while in the diffuser, it is the largest at design condition(Qd), followed by the large flow rate condition(1.25 Q_d),then the small flow rate condition(0.75 Q_d).The results above give a more in-depth understanding about the flow characteristics in such pumps, which will help in the optimization design and obtaining ahigher pump efficiency.

关 键 词：进口含气率 气液混输泵 流场特性 旋涡 数值模拟 

分 类 号：TH312[机械工程—机械制造及自动化]