Conditions Of Ζ,φ For The Low Specific Speed Centrifugal Pump Impellers Without Divorced

Fluid machinery is one of the most useful machinery of dynamic engineering. Low specific speed centrifugal pump comprise a large proportion of fluid machinery, and have more and more application in varied fields. Impeller is a important flowing part in centrifugal pump, and the impeller design, better or not, has great effect on hydraulic performance of the pump. Recently, with rapid growth and wide application of computer technique, the Computational Fluid Dynamics (CDF) method become a powerful tool on the optimal design of low specific speed centrifugal pump. So, this experiment utilized CFD to compare the capabilities of various designed impellers based on same geometric parameter(inner and outer diameters, width of inlet and outlet and setting angles). And in this paper, we apply two impeller number blades and four wrapping angles.Based on the given references of the pump, we design and optimize impellers. The blade were designed to be cylindrical for various wrapping angle and number of blades and a voulte was designed at same time to match. Cylindrical blades are extensively used in low specifice speed impellers, and easily design and produce. Based on Hermit interpolation method in a polar coordinate system, we acchieve a new type of cylindrical blades. The most notable feature of the new curve is that its wrapping angle can be specified by designer.After synthetic comparing about a variety of CAD/CAM software, the UG with mighty curve creation power was chose as the three-dimension model plane and AutoCAD for the two-dimension model, FLUENT is chosed as the three-dimension numerical simulation plane for the impellers.In the simulation of this paper, take the flow as three-dimentional steady flow. Then, simulates the flow fields inside the centrifugal pump impellers. We also analyzed the velocity distributions and pressure distributions within the centrifugal impellers according to their numerical simulation results. Different blades of impeller has different flow state. A good agreement was showed between the simulation results and the theoretical results. Compare with their inner flow velocity, pressure distribution, we can know which type of blade is better for the hydraulic performance with suitable wrapping angle and blade number.