叶片包角对离心泵性能的影响

Relationship between Wrap Angle of Impeller and Performance of Pump

在保证离心泵主要几何参数不变的前提下,使用Hermite插值方法对叶片包角为90°、120°、150°和180°的4个叶轮进行叶片绘型。数值模拟分析了不同叶片包角与离心泵性能的关系。结果表明,叶片包角因改变叶轮出口相对速度液流角而使离心泵扬程和功率特性发生变化,其效果与改变叶片出口安放角类似。叶片包角增大的同时叶轮流道内的脱流与漩涡也随之减小,流动更贴近叶片型线,但叶轮流道内的摩擦损失也随之增大,离心泵存在一个使其效率最高的最佳叶片包角。

The influence of relationship between wrap angle of impeller on performance of a pump was analyzed with the same main dimensions of centrifugal pumps unchanged.Blades were shaped using Hermite interpolation method.The wrap angle of impellers used in this investigation is 90°,120°,150°and 180° respectively.The result of numerical simulation indicates that the wrap angle changes the head and power characteristics by changing the relative velocity angle in impeller outlet.The effect of the different wrap angles is similar to that of the different impeller outlet blade angles.The bigger the wrap angle is,the smaller the separation and vortex in impeller passages are.With the wrap angle increases,the streamlines and blade profiles are getting similar,but the friction loss in impeller passages is getting large.So there exists an optimum wrap angle that corresponds to the highest efficiency of a centrifugal pump.