A general alternate loading technique and its applications in the inverse designs of centrifugal and mixed-flow pump impellers  

作　　者：WANG ChaoYue WANG FuJun AN DongSen YAO ZhiFeng XIAO RuoFu LU Li HE ChengLian ZOU ZhiChao 

机构地区：[1]College of Water Resources and Civil Engineering,China Agricultural University,Beijing 100083,China [2]Beijing Engineering Research Center of Safety and Energy Saving Technology for Water Supply Network System,Beijing 100083,China [3]China Institute of Water Resources and Hydropower Research,Beijing 100038,China [4]China Water Resources Beifang Investigation,Design and Research Co.Ltd.,Tianjin 300222,China

出　　处：《Science China(Technological Sciences)》2021年第4期898-918,共21页中国科学（技术科学英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant Nos.51836010,51779258,51839001);the National Key Research and Development Program of China(Grant No.2018YFB0606103);the Beijing Natural Science Foundation of China(Grant No.3182018)。

摘　　要：For the inverse designs of centrifugal and mixed-flow pump impellers,clarifying the generation process of secondary flows and putting forward corresponding suppression measures is an important approach to improve the impeller performance.In this paper,to provide a better qualitative insight into the generation mechanism of secondary flows in the impeller,a simple kinematic equation is derived based on the ideal assumptions,which indicates that the potential rothalpy gradient(PRG)is the most important dynamic source that actively induces secondary vortical flows.Induced by the natural adverse PRG on the S1 and S2 stream surfaces,two typical secondary flows,H-S and P-S secondary flows,are clearly presented.To specially suppress these typical secondary flows,a general alternate loading technique(GALT)is proposed,aiming to adjust the real blade loadingδp to control the PRG features.At the blade fore part,theδp on the hub streamline should be slowly increased to avoid breakneck growth of the potential rothalpy to reduce adverse streamwise PRG on the S2 streamsurface.At the blade middle part,theδp should be moderately decreased to reduce adverse streamwise PRG on the S1 streamsurface.At the blade aft part,the difference in theδp between the shroud and hub streamlines should be decreased faster to control the exit uniformity.By applying the GALT to the impeller designs of three typical pump types in hydraulic engineering,the organizational effect of the PRG on fundamental flow structures is proven.The GALT can effectively control the PRG distributions and suppress the secondary flows,thereby widening the pump’s high-efficiency zone,improving flow uniformity and suppressing pressure fluctuations.Compared with the current Z-G method and the ALT,the GALT can meet the requirements of"de-experience"better,thereby enabling the designers to obtain good products explicitly and quickly.

关 键 词：alternate loading technique inverse design centrifugal pump mixed-flow pump IMPELLER potential rothalpy gradient 

分 类 号：TH31[机械工程—机械制造及自动化]