Study On The Numerical Simulation Of The Influence Of The Inlet Conduit To The Pump Operating Performance

The inlet conduit is one of the important parts of large pumping system. It is the transit section between the front pool and pump blades, the function of which is to adjust the water flow and guide it change direction and accelerate as smoothly as possible, satisfying the design requirements.The bad flow situation in the inlet conduit will lead to the phenomena of dropping flow and swirl inside the pump with the results of uneven pressure distribution in the blades, the increase of energy loss inner the pump and the deterioration of the cavitations. The pump data provided by the pump factory is obtained in the professional lab, So the data is different from the fact in the practical pumping system. In order to predict the pump operating character, it is necessary to know how the inlet conduit affects the pump's inner flow.In this paper, the RANS equation and RNG-turbulent model are applied to simulate the pumping system, which is composed of the inlet conduit and the blades. The special software CFX-UILD (Patran) and CFX-TurboGrid is used to create the series of inlet conduits and the propeller pump blades. In the CFD software CFX-TASCflow, the inlet conduit and the blades are assembled and the boundary conditions are set. Finally the velocity, pressure, head, power and efficiency are obtained through calculation.In this paper, nine different inlet conduits are analyzed and compared. It appeared that both R and L affect the pump inner flow and the operating performances. The computer results show that R=1.0D and L=0.7D is appropriate.