Internal Flow And Energy Performance Prediction Of Multistage Guide Vane Centrifugal Pump

In the R&D of hydraulic machinery computer-aided design tools become increasingly important to support the machine design and performance prediction. In particular, Computational Fluid Dynamics (CFD)are more and more used by pump manufacturers. On one hand it is applied in order to save experimental resources and shorten the period of exploitation for new productions, on the other hand it is able to show detailed flow features, which are not assessable by experimental tools,so the research is very significant in theory and economy.In the paper,at first, three-dimensinal modeling and meshing of the impeller and vaned diffuser through a centrifugal pump stage have been performed .and then Steady state computations of the flow in many working conditions have been done and the pressure and velocity distribution in multistage pump are obtained,so some opinions is given for improvementat last,we can get the performance curve,such as H-Q curve and -Q curve by collecting the data.The main research production of the thesis is as follows: 1 , Some experiences are acquired about how to design the model and how to select the real object or virtual object and how to use meshing and lighting technics by modeling the impeller and vaned difruser.2, The pressure and velocity distribution in components of multistage pump such as inlet , outlet N blade , hub , cashing, meridional , spanwise. positive diffuser, diffusing and reversing diffuser are obtained: 1) There is reverse flow in inlet of impeller in the low and design working conditions that shows the method of increasing flux is taken.2)Circumfluence is observed outlet .That it is great in low and design working conditions is conflict with the traditional theory which considers the circumfluence is independent of the working conditions.3) Some opinions is given for improvement of designing the reverse diffuser such as redesigning the linetype,the width along with the axis or the thickness of blades and so on.3, We get the performance curve through a centrifugal pump stage by calculating.The comparison of the prediction with the experiment shows that the errors are low comparing with the experimental data at design condition,but the errors are high at other working conditions especially at low flux.