摘要
运用速度系数法获得叶轮基本几何参数,根据给定的叶轮流道过流断面面积分布规律与叶片包角分布规律调整叶片轴面轮廓形状,并由所建立的短叶片偏移角与Wiesner滑移系数之间的关系确定短叶片位置.基于该方法在相同设计参数(扬程、流量、转速等)条件下设计了4种短叶片参数不同(叶片长度分别为0.75,0.65,0.55和0.45倍长叶片长度)的低比转数离心泵叶轮,并采用RANS控制方程组和RNG k-ε湍流模型对所设计的离心叶轮流道的三维湍流流场进行计算分析,研究了这4种短叶片对沿流道的速度分布、压力分布及离心叶轮整体水力性能的影响.结果表明:添加短叶片能明显提高叶轮扬程,但过长的短叶片会增加冲击损失与摩擦损失;扬程增加量会随短叶片长度的减小而增大;通过选取合适的设计参数并合理地放置短叶片可以改善流态,提高水力性能.
By using empirical correlations,basic geometry parameters of impeller were obtained.The impeller profile was adjusted according to given flow cross section area distribution and wrap angles distribution;and the position of the splitter blade was determined according to the relationship between the splitter blade deviation angle and Wiesner slip factor.Based on this method,using the same design parameters（head,capacity,rotation speed,etc） with different factors,four different low specific speed centrifugal pump impellers with different splitter blades（75%,65%,55%,45% long blade length） were designed.By using RANS equations with RNG k-ε turbulence model,three dimensio-nal turbulent flow fields of the designed impeller channels were calculated and analyzed.The effects of four different splitter blades on velocity distribution,pressure distributions along the flow channels and hydraulic performance of centrifugal pump impellers were studied.The results show that the hydraulic head of impeller can be improved by adding splitter blades;long splitter blades will increase hydraulic loss and fraction loss and the increased amount of hydraulic head increases as the splitter blade length decreases.With properly-selected design parameters and properly-positioned splitter blades,the flow in the pump can be improved and its hydraulic performance can be enhanced.
出处
《排灌机械工程学报》
EI
北大核心
2013年第4期300-304,324,共6页
Journal of Drainage and Irrigation Machinery Engineering
基金
国家自然科学青年基金资助项目(50809075)
中国石油大学(北京)基金资助项目(KYJJ2012-04-11)
关键词
离心泵
低比转数
二元理论
水力设计
性能预测
centrifugal pump
low specific speed
two-dimensional flow theory
hydraulic design
performance analysis
