旋流自吸泵内部流场数值模拟及PIV试验  

PIV measurements and CFD computations of internal flow characteristics of rotational flow self-priming pump

作　　者：刘轲轲 王春林[1] 冯一鸣[1] 胡蓓蓓 LIU Keke;WANG Chunlin;FENG Yiming;HU Beibei(School of Energy and Power Engineer,Jiangsu University,Zhenjiang,Jiangsu 212013,China)

机构地区：[1]江苏大学能源与动力工程学院

出　　处：《排灌机械工程学报》2019年第12期1025-1030,共6页Journal of Drainage and Irrigation Machinery Engineering

基　　金：国家自然科学基金资助项目(51109094);江苏高校优势学科建设工程项目

摘　　要：为了获得旋流自吸泵的特殊蜗壳结构对于其自吸性能的作用,通过二维PIV测量和三维软件CFX,获得了3个测试工况下旋流自吸泵的内部流场和蜗壳内部的速度场.结果表明,导流壁与叶轮出口在蜗壳内形成的"喷嘴"和"扩压器"形状,分别促进了气-水混合液和气泡流的形成.通过"喷嘴"的液体,其流向涡量、旋转速度和流动均匀性得到提高.液体和叶轮流道1内的气体发生动量交换,气体被压缩并且分散成不同大小的气泡,而液体分散成液滴,形成气-水混合液.通过"扩压器"的气体被进一步压缩,大气泡破裂后形成无数微小气泡,而液滴积聚成液体,形成气泡流.气液分离室内形成2个大小和旋向不同的旋涡,由于离心力作用,气泡流中的气体和液体分离,气体从泵出口管逸出.液体分离回落被凸台阻挡,与凸台的碰撞使液体中夹带的气泡再次分离,而液体流回蜗壳,再次参与上述过程,直到空气从吸入管中排净.The internal flow fields of a rotational flow self-priming pump under three test conditions by using the two-dimensional particle image velocimetry measurements and the three-dimensional Navier-Stokes code CFX simulations were presented. The velocity fields of the special volute were analyzed in detail. The detailed flow analysis shows that the special volute contributes to the self-priming characteristic. The diversion wall and the outlet of the impeller constitute a ″nozzle″ and ″diffuser″ which promote the formation of gas-liquid mixture and the bubble flow. The streamwise vorticity and the maximum swirl velocity as well as the uniformity of the flow are increased through the ″ nozzle″. An exchange of momentum occurs between the liquid and gas in passage 1. The gas is compressed and dispersed into bubbles of different sizes and water is dispersed into droplets,and the gas-liquid mixture is formed. The gas is further compressed through the ″diffuser″. Large bubbles break up into countless tiny bubbles,while droplets are aggregated into liquid,forming bubble flow. Two swirls of different sizes and directions are formed in the gas-liquid separation chamber,which make the gas and liquid separated due to the centrifugal force. The gas flows to the center and exits from the outlet pipe. The separated liquid moves downward and comes into collision with the boss structure. The collision makes the gas bubbles entrained with the liquid separated again. The liquid flows back and once again participates in the above processes until all the air has been evacuated from the suction line.

关 键 词：旋流自吸泵 CFD 自吸特性 内部流场 

分 类 号：TH317[机械工程—机械制造及自动化]