Theory And Software Development On Characteristics Prediction Of Centrifugal Pumps

The pump characteristics prediction is such that using the geometry parameters of pump's components such as impeller, volute, diffuser and the pattern of pump interior flow to evaluate pump's performance. It can not only shorten the cycle of product research and development but also reduce the cost of the pump design and manufacture. The pump characteristics prediction has been a very important subject in pump field all the time, many experts and researchers have done a lot of study on the subject. But the result is still not accurate enough to satisfy the need of engineering application, and there is still no practical software of the pump characteristics prediction in China. Therefore, it is necessary to have a serious study on the characteristics prediction of centrifugal pumps, which is both of academic meaning and social economy benefits. The main research contents of this paper are below:(1) The present situations and trend on characteristics prediction of centrifugal pumps are summarized. The advantages and disadvantages of several main methods on pump characteristics prediction, such as the hydraulic loss, the flow field analysis and the neural network are compared.(2) The paper researches deeply the demonstration process of pump theoretical head formula and concludes that the precision of theoretical head is determined mainly by slip coefficient.(3) The Stodola, Stechkin, Pfleiderer and Weisner slip coefficient formula are compared, and the research indicates that Weisner(ns<65) and Stechkin(ns>65) are more accurate for centrifugal pump. Based on practical calculation results of many excellent hydraulic model and experiment results, the two formulas of Weisner and and Stechkin are modified, and the coefficients are calculated by regression analysis method.(4) The hydraulic efficiency formula, volume efficiency formula and mechanical efficiency formula are analyzed. According the practical calculation, the suggestions on how to use these formulas are given.(5) The disk friction loss formula are studied and the author concludes that the formula should be chosen by specific speed. The chosen formulas are modified and the coefficients are calculated by regression analysis method.(6) The hydraulic loss evaluation formula are analyzed based on the study of...