Boundary Layer Theory In Centrifugal Pumps Of Liquid-Solid Two-Phase Fluid And Its Application On Vane's Design

The hydraulic transport technique of solid matters in pipelines has the history of 120 years. In resent years,it is developing rapidly. With its advance,the centrifugal pumps of liquid-solid two-phase fluids,which are the vital devices in hydraulic transport,are evolving. The perfection of designing theory and method has been an important project of professors,researchers in industrial departments,universities and institutes in every country.In the basis of the references on a centrifugal pump of two-phase fluids from domestic and oversea,its theory of boundary layer is presented and set up and the modular curve equation of vane is received in this paper. It divides into 7 chapters.The introduction is in chapter one,which summarizes the research results of centrifugal pump of two-phase fluids in domestic and oversea and illuminates the research aim,significant and main contents.In chapter two,according to N-S equation,considering the couple between liquid and solid,the double-fluid model is used to respectively set up momentum equations of two-phase fluids in condition of basic hypothesis,which are general equations of two-phase fluids. Simplifying the equations in boundary layer,the momentum differential equations are required and the boundary conditions are given. In the same time,the simplifying equations and their solutions,in which solid grain satisfies in boundary layer.In chapter three,the momentum integral equations and their solutions of two-phase fluids in boundary layer are given and the no-disturbance solutions on the surface ofvane are required. Leading into the disturbance factor of no-dimension and thicknesscoefficient ks in boundary layer,the numerical method of finite approximation is usedto calculate the boundary layer.In chapter four,according to the analysis on the boundary theory and velocity field of main fluid zone of two-phase fluid pumps,the parameter equations of vane's modular curve of centrifugal pump are given,which contact the boundary' layer and Eular theoryof two-phase fluid pump by the fixing angel of vane as variable and leading into thevelocity coefficient A. The results show that,in designing process of vane's modularcurve of centrifugal pump,the determination of the total shape and parameters relates the flow properties of two-phase fluid and output ability of pump,or the design of themodular curve of centrifugal pump is the kernel of hydraulic design. Then,only a given curve satisfied by the conditions of import and outlet of vane wheel as its modular curve will neglect the middle varying processes of in vane wheel,which reflect microscope properties in some degree-flow properties in boundary layer. Leading into the velocity-coefficient unifies the boundary layer and Eular theory in the design process of vane,which extends the area of selection of vane's curves and provides a valuable object function for the optimization design of vane.In chapter five,as one of the applications of boundary layer theory on two-phase fluid pump,the calculation process and example analysis in vane design are given and the stability and convergence of algorithms and programs and rules showed in calculation are required.The performance contrast test of the centrifugal pump is in chapter six.The conclusion of the paper is in chapter seven.