The Research On Design Method Of Impeller Of Medium-high-speciifc-speed Centrifugal Pumps Based On CFD

Impeller design of medium-high-specific speed centrifugal pumps is usuallyone-dimensional design theory and has few research.In this study, two-dimensionalflow theory is adopted to design impeller of medium-high-specific speed centrifugalpump.Compared with impeller designed by one-dimensional theory, internal flowregulation pattern in two-dimensional impeller and pump performance are presented,based on CFD numerical simulation by the software Fluent6.3.The main work andachievements are as follows：1、 According to the given set of operating conditions, both traditionalone-dimensional impeller and six two-dimensional impellers,which have six differentvelocity moments distribution,based on two-dimensional flow theory with ωu=0,are designed.2、Three-dimensional solid formations and soild meshes of the impellers inspatial cylindrical coordinate system was presented.And it is laying a reliable basisfor improving CFD and performance prediction of inner flow of the centrifugalpump.3、 In this paper, the numerical simulation calculation was based on thecontinuity equation and Reynolds-average Navier-Stokes equation. The controlequation was solved by using standardk εturbulence model and SIMPLECalgorithm. Compared with velocity distribution assumptions in two kinds of design theory,meridional velocity and velocity moments distribution of blades were simulated and CFDanalysis in the real flow field is carried out on these impellers.4、The three-dimensional turbulent flow fields in the designed pumps wereanalyzed respectively in different working operations, which are0.4Q、0.6Q、0.8Q、1.0Q1.2Q.The distribution of velocity and pressure of the first four impellers indesign operation were emphatically analyzed and compared.Main innovations in this research work:1、 Adopting two-dimensional design theory to the design of impeller ofmedium-high-specific speed centrifugal pumps.An analysis on the difference of flowregulation between the assumption of two kinds of design theory and the real flowfield is presented.2、A two-dimensional impeller with potential flow is designed and the relationbetween velocity moments at the import and export of impeller and energy head and efficiencyof pump. Due to the limits of time and conditions and my lack of experience, there are alot of works not done well. It is not satisfied that the Hydraulic model of thetwo-dimensional impeller of medium-high-specific centrifugal pump in this paper,and the distribution and value of velocity moments are not enough advanced too.Therehas further room for further study.