Considering the complexity of the flow state with high head, low capacity and long passage, the hydraulic design of low specific speed centrifugal pump impellers was based on similarity theory and its hydraulic performance is highly dependent on the model of impeller and experience of designer. A numerical method was put forward combining the advantages of similarity theory design and 2D theory design, adopting quasi-orthogonal method and Euler energy equation to calculate meridional velocity distribution, adjusting the meridional profile according to the cross section area, drawing blade shape by point-by-point integration method, thickening blade and smoothing leading edge of blade by using Bezier curve. The design of the impeller (specific speed of 67) was completed. The results show that the low specific speed centrifugal pump impeller design can be achieved through the adjustment of parameters, and the design data from the blade surface is complete. It is easy to process and manufacture the numerical control machine tools. The design of the impeller can be optimized using various optimization program.%低比转速离心泵叶轮因扬程高、流量小、流道长而使内流状态复杂,其水力设计普遍采用基于相似理论的方法,叶轮水力性能高度依赖叶轮模型和设计者的经验.综合考虑相似理论设计经验成熟和叶轮空间流动理论设计的优势,采用二元流动理论,应用准正交线法绘制轴面流网,结合欧拉能量方程,进行轴面速度的迭代计算,根据轴面速度的分布要求,不断优化轴面流道轮廓,用贝塞尔曲线对叶片头尾部进行修圆,依据该方法编制的程序完成比转速为67的叶轮水力设计.结果表明:通过对相关参数的调整可实现低比转速离心泵叶轮的快速设计,设计所得叶片表面数据齐全,便于数控机床加工制造,还可结合各种优化程序对时轮进行优化设计.
展开▼
