摘要
目的在改善泵喷推进器(泵喷)水动力性能的同时,兼顾其空化性能。方法以某前置泵喷为原型,采用基于密度修正的RNG k-ε双方程湍流模型,结合Zwart空化方程,数值研究定子叶片数(N_(s)=6~10)对空化性能的影响。结果泵喷空化主要为叶梢涡空化和叶片表面的片状空化,而时-频空化曲线与叶片数目有关,其中单转子表面空化与定子数目相关,而总空化面积与转-定子影响有关。结论增加定子叶片数虽然提高了泵喷推力和扭矩,但转子叶片及叶梢负荷增加,使空化范围大幅度增加。最终N_(s)从6增加到10时,总空化体积涨幅超过5倍。分析空化流动中的涡量输运方程发现,膨胀收缩项在空化演化占主导作用,并且随着定子叶数的增加而增大。
To improve the hydrodynamic performance of pump-jet propulsor(PJP)and take into consider its cavitation performance,this work employs the RNG k-εturbulence model combined with the Zwart cavitation equation to predict the PJP cavitation with various stator numbers(N_(s)ranges 6~10),and the turbulent viscosity is corrected by DCM(Density Corrected Model)approach.The results show that the PJP cavitation is mainly the tip cavitation and sheet cavitation on the blade surface,while the time-frequency curves of cavitation are closely related to the number of blades.The single-rotor surface cavitation is associated with the stator number,whereas the total cavitation area is determined by the interaction of the rotor and stator.Moreover,the increase of the Ns improves the PJP thrust,the load of rotor blades and blade tip also increases,thus causing the cavitation to occur more easily.The sheet cavitation increases sharply with the increase of N_(s)in radial and chord-wise directions,and the rise in tip cavitation is much smaller than that of sheet cavitation.Eventually,when N_(s)increases from 6 to 10,the total cavity volume increases by more than 5 times.Further analysis of the vorticity transport equation reveals that the vortex dilation term plays a leading role in the evolution of cavitation and increases within a certain range of chord-wise direction as N_(s)increase.
作者
李福正
黄桥高
潘光
孙国仓
LI Fu-zheng;HUANG Qiao-gao;PAN Guang;SUN Guo-cang(School of Marine Science and Technology,Northwestern Polytechnical University,Xi'an 710072,China;Key Laboratory of Unmanned Underwater Vehicle,Northwestern Polytechnical University,Xi'an 710072,China;Wuhan Second Ship Design and Research Institute,Wuhan 430205,China)
出处
《装备环境工程》
CAS
2022年第5期56-64,共9页
Equipment Environmental Engineering
基金
国家自然科学基金(51979226)
中央高校基本科研业务费专项(3102019HHZY030019,3102020HHZY030018)。
关键词
泵喷
空化
密度修正
定子叶片数
涡量输运方程
pump-jet propulsor
cavitation
density-corrected
stator number
vorticity transport equation
