离心泵叶轮平衡腔内液体流动特性及圆盘损失分析  

Analysis of Flow Characteristics and Disc Friction Loss in Balance Cavity of Centrifugal Pump Impeller

作　　者：董玮[1] 楚武利[1,2] 

机构地区：[1]西北工业大学动力与能源学院,西安710129 [2]先进航空发动机协同创新中心,北京100191

出　　处：《农业机械学报》2016年第4期29-35,共7页Transactions of the Chinese Society for Agricultural Machinery

基　　金：国家自然科学基金项目(51576162;51236006)

摘　　要：在离心泵0.8Qsp、Qsp、1.2Qsp流量工况点,外特性及平衡腔内流动特性数值计算结果与试验结果基本一致的基础上,研究平衡腔液体流场分布情况,绘制平衡腔内液体不同角度和半径无量纲圆周、径向分速度沿轴向分布曲线,分析平衡腔液体流动特性,计算平衡腔区域叶轮盖板外侧圆盘摩擦损失。结果表明:平衡腔液体流动存在核心区和两湍流边界层,主要流动特征为圆周剪切流与径向压差流。同一流量点,平衡腔流动核心区无量纲圆周分速度随半径的增大而减小,无量纲径向分速度近似为零,而湍流边界层液体受泄漏流影响较大,且不具有轴对称性。流量越小,同一角度和半径的平衡腔液体旋转角速度越小,平衡腔区域叶轮圆盘摩擦损失越大。泵内圆盘摩擦损失理论公式未考虑流量工况变化因素影响,且理论公式结果大于试验结果和数值计算结果。The disc friction loss and axial force calculation of centrifugal pump and flow characteristics of balance cavity liquid are closely related. At operating points of 0. 8Qsp,Qspand 1. 2Qsp,numerical calculation results and experimental results were basically consistent on performance of pump and flow characteristics of balance cavity. Distribution of velocity field was researched in the balance cavity. The distribution curve of dimensionless circumferential velocity component and dimensionless radial velocity component were drawn along the axial direction at different angles and radiuses of balance cavity to analyze the flow characteristics and calculate the disc friction loss in the balance cavity area. The results showed that flow core and turbulent boundary layer existed in the balance cavity liquid. The main flow characteristics were circumferential shear flow and radial differential pressure flow. The dimensionless circumferential velocity component of flow core decreased with the increase of radius,the dimensionless radical velocity component was approximately zero,while turbulent boundary layer liquid was greatly influenced by leakage flow,which was asymmetric under the same flow condition. The radical leakage flow in the sealing back-ring and the axial leakage flow in the balance hole of the impeller played an important part in the flow of radical velocity component at the turbulence boundary layer and circumferential velocity component at the balance holes area. The rotational angular velocity of balance cavity liquid at the same angle and radius increased with the increase of flow. The disk friction loss in the balance cavity decreased with the increase of the flow. Theoretical formula of disc friction loss did notconsider the effect of variable flow conditions on pump. The theoretical results were greater than the experimental results and the numerical calculation results.

关 键 词：离心泵 平衡腔 圆周分速度 径向分速度 圆盘摩擦损失 数值模拟 

分 类 号：TH311[机械工程—机械制造及自动化]