离心泵叶片开槽抑制空化数值模拟  

Numerical Simulation of Slotted Blade in Centrifugal Pump on Cavitation Suppression

作　　者：赵伟国[1,2] 翟利静 夏添 李尚升 ZHAO Weiguo;ZHAI Lijing;XIA Tian;LI Shangsheng(College of Energy and Power Engineering, Lanzhou University of Technology, Lanzhou 730050, China;Key Laboratory of Fluid Machinery and System, Gansu Province, Lanzhou 730050, China)

机构地区：[1]兰州理工大学能源与动力工程学院,兰州730050 [2]甘肃省流体机械及系统重点实验室,兰州730050

出　　处：《农业机械学报》2018年第12期150-157,共8页Transactions of the Chinese Society for Agricultural Machinery

基　　金：国家自然科学基金项目(51269011);流体及动力机械教育部重点实验室(西华大学)开放项目(szjj2017-093)

摘　　要：为了进一步提高低比转数离心泵的空化性能,提出在叶片压力面开槽的方法来抑制空化。针对离心泵运行过程中产生空化的流动特点,基于Kubota空化模型,采用SST k-ω模型对在相同工况下的离心泵中两相流动进行数值模拟与分析。模拟结果表明:叶片表面开槽后,离心泵各个工况下的扬程有所上升,在设计点扬程提高12. 8%,同时效率提高4. 2%。叶片开槽可以有效阻止低压区域向外扩张,改变压力的分布,对离心泵内各个阶段空化均有抑制作用。叶片开槽可以优化流场结构,使流道内的压力增加,减小空泡的体积分数。叶片开槽时离心泵叶轮内空泡体积在空化的各个阶段均小于无槽时叶轮内空泡体积,在空化发展阶段,开槽时空泡体积持续衰减。Centrifugal pumps are widely used to deliver liquid media in agriculture, pharmacy, industry, etc. Compared with the case delivering pure liquid such as water, centrifugal pumps not only have lower efficiency but also are subject to severe vibration, noise and erosion when delivering cavity two-phase flow. In order to further improve the cavitation performance of low specific rotation centrifugal pump, a method of making the blade slotted to control cavitation in a centrifugal pump was proposed. The slotted impeller blade near the inlet of centrifugal pump was studied. According to the flow characteristics of cavitation in centrifugal pump and the cavitation dynamics model of Kubota cavitation model, the SST k-ω model was used to simulate and analyze the two-phase flow in a centrifugal pump under the same working conditions. The simulation results showed that after the blade surface was slotted, the head of the centrifugal pump was increased, and the head of the centrifugal pump was increased by 12.8% at the design point, and the efficiency was increased by 4.2%. The slotted blade can effectively prevent the low pressure region from expanding outward, change the pressure distribution and inhibit the cavitation in every stage of the centrifugal pump. The slotted blade can optimize the flow field structure, increase the pressure in the flow channel and reduce the volume fraction of the cavitation. The cavitation volume of centrifugal pump impeller in every stage of cavitation was smaller than that of impeller without slot when the blade was slotted. In the stage of cavitation development, the volume of slotted space-time bubble continued to decay.

关 键 词：离心泵 叶片开槽 空化 数值模拟 

分 类 号：TH311[机械工程—机械制造及自动化]