Study On The 3D Turbulent Numerical Simulation Of The Two-way Passage Vertical Pumping System

The two-way pump stations with two function for irrigation and drainage are applied widely in riverside, littoral areas, seaside and in the urban flood control. Usually, the total head of these pumps are low, axial-flow pumps are applied commonly, two-way passage is adopted to achieve two-way pumping function. Research and develop these pump stations is very import and has realistic significance.In this paper, it takes two-way passage axial pump station as research model, the RANS equation and the RNG k-εturbulent model are applied to simulate the 3D steady turbulent flow in the whole pumping system, which is composed of inlet passage, outlet passage, inlet diffuser, outlet diffuser, impeller and diffuser. The Commercial fluid-computation software such as ANSYS ICEM-CFD, CFX-TurboGrid 2.2 and CFX5 is used to create the series of whole pumping system and compute. In the condition of any other construction is same, four pumping systems with different outlet diffuser are simulated. Based on viscous numeration of the whole pumping system, the velocity, pressure, head, power and efficiency in varying work conditions are obtained, a predication model of hydraulic performance are set up.The results of computation indicate that when fluid flowing from one side of the two-way passage, there will come into being no fluid areas in the other closed side .Because the space in the closed side is too big. Flow situation in the two-way passage is bad with the phenomena of circumfluence and vortex. The efficiency of the pumping system is low.The difference of the outlet diffuser which is critical to improve the efficiency of the pumping system, affect running performance of pumping system greatly. The curvilinear outlet diffuser is superior to straight-linear outlet diffuser apparently. Outlet diffuser diffuses fluid sufficiently and recovered energy effectively.In this paper, a good agreement was achieved between calculation data and experience date. The precision of computation and prediction adapts engineering applied research.