Optimization Hydraulic Design Of High Specific Speed Axial Flow Pump

The guide vanes and the impeller of high speed axial pump are the most important parts of the whole flow pump unit. They are also the main energy transition parts. It is mainly through studying guide vane and impeller in order to improve the performance of the pump unit. So it has a practical significance of the studying in the parameters of the impeller structure and the guide vane’s position in the pump unit performance.Different parameter plans have different affection on axial flow pump’s performance.It’s necessary to study the influences of different plans of parameters by analyzing axial pump’s inside flow and outside characteristics. Simulating and analyzing the three different plans by the way of CFD,we got some rules and these rules will be the reference for the design hydraulic optimization. of high speed axial pump.The main contents mentioned in this paper are as following:1. Combined with AutoCAD and Pro/E software to the pump three-dimensional molding, using ICEM to intake conduit, outlet conduit, tube bending to mesh generation, and using Turbo-grid to the impeller and guide vane body to mesh generation;2. Using CFD software (ANSYS CFX12.0), based on Renault time even equation and the standard process turbulence model, in three different cases (different leaf thickness, different leaf number, different diffuser, import and export impeller parallel spacing) for the whole channel numerical simulation; Capture the velocity distribution and static pressure distribution, and other important flow parameters and contrast analysis;3. Through analyzing the calcution result with CFX-Post, we could see:(1)On the different thickness of blade numerical simulation analysis shows that:when the flow become small, the change of blade thickness does not cause larger changes, the lines of its head, power and efficiency are basically coincident; when the flow comes in the design flow, Accompanied by the decreases of blade thickness,the ternd of the head line changed in the same flow, the trend looks like at the same flow rate,with blade thickness increasing, the head, power declines, in terms of efficiency, we can clearly see that, although there are similar to the above trend, but at some point or the overlap phenomenon; when the flow become large, its head, power and efficiency of basic does not have too big change. (2) On the different number of blade numerical simulation analysis shows that:compared with the three blades, the head and efficiency of the four blades looks better in the case of small flow; while in the high flow situation, basically coincidence. And the right side portion of saddle area moves higher.(3) On the parallel space S of axial flow pump guide vane inlet side and the outlet side of impeller blade changes numerical simulation analysis shows that：when the S become small (0.05D～0.1D), under the design flow, the of circulation of the outlet velocity distribution and static pressure distribution looks relatively uniform, on the pump performance There are certain promotion.Beyond0.1D, the outlet velocity distribution of circulation and pressure distribution are not very ideal, the alteration of S have not much effect in the performance of the pump. Visible changes to the S, in a certain range of the pump unit performance or influential. Simply by changing the spacing of S to improve the overall performance of the pump section or confined to a certain extent, according to the actual working condition of pump levels, to select the corresponding distance S.