Research Based On Boundary Layer Theory On The Centrifugal Pump For Solid-liquid Two-phase Fluids

The centrifugal Pump for solid-liquid Two-phase fluids is the key equipment that the solid supplies transports by water pipeline, both sending efficiency and maintaining cost while sending have direct relations with the centrifugal pump. The main invalid form of centrifugal pump is the wearing and tearing of the blade of the impeller. The choice of impeller parameter and the sureness of blade type line have direct influence to the flowing losses and the resisting ability of wearing and tearing. Having consulted a large amount of relevant materials, boundary layer theory is chosen as the basic theory for studying the design method of the blade type line. Based on momentum differential equations of liquid and solid phase of the solid-liquid two-phase fluids and on the solid liquid phase coupling equation, have derived the blade type line equation based on boundary layer theory. Because both boundary layer separate and the influence of tail shedding area will enhance the wearing and tearing on the boundary that fluid flows and reduce water conservancy efficiency sharply, so the Criterion that boundary layer separates is discussed, and then the Design method of blade type line is summarized. Studying on the function of wearing and tearing, the Entry angle choose method that can largely reduce tail shedding area influence is derived, thus can reduce the wearing and tearing to the blade of the solid particle effectively. So not only avoided the setting-up and work on the complicated mathematics model of the three-dimensional fluid, but also the boundary layer theory is developed on the Entry angle choose method. In this article I choose type 100 dreg thick liquid pump as the instance , using the boundary layer theory designs the parametric equation of the blade type line. Using Pro/E three-dimensional parameter model of the impeller is set up, this blade model is set up by feature sweep a thin board of Pro/E based on datum line that blade parametric equation of line that derived from boundary layer theory. So this model accord with boundary layer theory, meet no boundery layer separate terms. Utilizes the family table of Pro/E, has realized the dynamic modeling of the impeller . In this article the stress to the individual blade of the impeller has been carried on finite element analysis by ANSYS, and then the logarithm spire blade that the dreg thick liquid pump adopts extensively carried on modeling and analyses with the finite element under the seem condition, compareing with the two result, it indicate blade that designed by the theory of boundary layer the stress is more even on the basis of border, the stress maximum nearly reduces 18%, so we can learn that using boundary layer theory can reduce the wearing and tearing of the impeller effectively, thus can improve the life-span of the impeller and pump. Research approach and conclusion of this article, boundary layer theory of the solid-liquid two-phase fluids centrifugal pump has developed and perfected, and provide an important reference of the two-phase fluids pump design.