叶片数对离心泵瞬态空化特性的影响  

The Effect of Blade Numbers on Transient Cavitation Characteristics of Centrifugal Pump

作　　者：赵伟国[1] 马亮亮 张舒研 咸丽霞 ZHAO Wei-guo;MA Liang-liang;ZHANG Shu-yan;XIAN Li-xia(College of Energy and Power Engineering,Lanzhou University of Technology,Lanzhou,Gansu,China,730050)

机构地区：[1]兰州理工大学能源与动力工程学院

出　　处：《热能动力工程》2019年第11期1-7,共7页Journal of Engineering for Thermal Energy and Power

基　　金：国家自然科学基金(51269011)~~

摘　　要：为研究叶片数在离心泵设计工况下对瞬态空化特性的影响,基于SST k-ω湍流模型和Zwart空化模型,以3种叶轮叶片数的离心泵为研究对象对其内部空化流动进行三维非定常数值模拟。结果表明:对于3组不同叶片数(Z=4、5、6)的叶轮,随着叶片数逐渐增加,离心泵扬程增加,但效率无明显差异;不同叶片数离心泵的空化特性曲线不同,临界空化点压力以及扬程断裂值不同,3种叶轮方案在无空化时的扬程分别为44.8、41.8和39.2 m,扬程断裂的相对值分别占其扬程的27%、25%、32%,即Z=5的叶轮离心泵扬程下降最少;在叶轮的一个旋转周期内,随着时间的增大,Z=4的空泡体积逐渐增加,Z=5和Z=6的空泡体积逐渐减小;叶片数较少时,叶轮流道内相对轴面漩涡运动剧烈,流体的绝对速度降低,造成泵压头的衰减,加速空化发生。In order to study the effect of blade numbers on transient cavitation characteristics under the design condition of centrifugal pump,three-dimensional unsteady numerical simulation for the internal cavitation flow with three kinds of impeller blade numbers are conducted based on the SST k-ω turbulent model and Zwart cavitation model.The results show that for the three groups of impeller with different blade numbers(Z=4,5,and 6),head of centrifugal pump increases with the blade number,while its efficiency has no significant difference.Head-drop curve of the centrifugal pump for different blade numbers is different,and the pressure of critical cavitation point and the head fracture value are different.The head of three schemes are 44.8 m,41.8 m and 39.2 m,respectively.When there is no cavitation,the relative values of the head fracture account for 27%,25%,and 32% of the head,respectively,with Z=5 impeller centrifugal pump having the least head drop.During one rotation period of the impeller,as time goes on,the bubble volume of Z=4 impeller gradually increases,but the bubble volume of Z=5 and Z=6 gradually reduces.When the blade number is smaller,the relative axial vortex motion in the impeller flow channel is severe,and the absolute velocity of the fluid is reduced,causing the attenuation of the pump head and acceleration of cavitation.

关 键 词：叶片数 离心泵 空化特性 数值模拟 

分 类 号：TH311[机械工程—机械制造及自动化]