Analysis of Complex Flows in the Whole Passage of an Axial Flow Pump

To systematically study the spatial flow characteristics inside an axial flow pump, based on three-dimensional Navier- Stokes governing equation and renormalization group(RNG) k-epsiv model, computational fluid dynamics (CFD) work on rotating turbulent flows with complicated curved boundaries was practiced. Unstructured meshes and the semi-implicit method for pressure linked equation (SIMPLE) algorithm were adopted. Major attentions were placed on pressure distribution in inlet, impeller and vane zones under design operation condition. Three viewpoints are obtained. (1) From blade inlet to outlet, hydrostatic pressure decreases firstly and then increases on suction surface. On pressure surface, hydrostatic pressure increases radially from hub to tip. The total pressure on suction surface is obviously lower than that on pressure surface. (2) The lowest pressure appears near the leading edge of suction surface, approaching the blade tip, where cavitation occurs with great possibility.(3) From inlet to outlet of vane passage, there is no pressure lower than critical cavitation pressure and hydrostatic pressure increase along the bulk flow direction. Numerical simulation result here can be referred in axial flow impeller design and relevant flow analysis.