离心泵叶轮穿孔对空化性能的影响

为分析离心泵叶轮开孔对空化性能的影响,选取一普通离心泵作为研究对象,在进口易空化区不同位置做不同直径的贯通孔,利用CFD仿真软件,对模型进行全流道三维定常湍流空化数值模拟,研究在不同进口汽蚀余量条件、不同开孔位置和不同开孔直径对离心泵性能影响。结果表明:开孔会造成叶轮内能量损失,损失大小与开孔直径和孔内平均流速正相关;开孔对离心泵空化性能影响主要取决于流体在吸力面与压力面之间的能量差和开孔造成的能量损失之间的差值,差值为正则抑制空化,差值为负则加剧空化;扬程和效率随开孔直径先升高后下降,当穿孔直径为3 mm时,达到最大值;开孔会影响叶片吸力面压力及流场分布;综合看,在C=0. 5流面开孔优于在C=0. 9流面开孔。

Effect of Blade Perforation on Centrifugal Pump Cavitation Characteristics

The effect of blade perforation on centrifugal pump cavitation characteristics is investiated in this paper.First,an ordinary centrifugal pump is selected as the research object,and perforated with different diameters and different positions at the cavitation zone.By using the CFD simulation software,the numerical simulation of three-dimensional turbulent cavitation in the full flow channel is carried out to study the effect of different position and diameter of perforation on the performance of the centrifugal pump under the different NPSH.The results show that,the perforation will cause energy loss in the impeller,which is positively related to the diameter and the average velocity inside the holes.The effect of blade perforated on centrifugal pump is mainly determined by the difference between the energy difference between the suction surface and the pressure surface and the energy loss caused by the perforation.The perforation of the centrifugal pump can increase the head and efficiency of the centrifugal pump slightly first and then decrease.When the perforation diameter is 3 mm,the maximum value is reached.Perforation will change the pressure and velocity distribution on the suction of blade,and perforating at the middle stream surface( C=0.5 ) is better than C=0.9.