Performance prediction of Centrifugal Pumps with variations of blade number

Centrifugal pumps are used extensively for hydraulic transportation of liquids over short to medium distance through pipelines where the requirements of head and discharge are moderate. At present, the influence of blade number on inner flow field and the characteristics of centrifugal pump have not been understood completely. The use of numerical analysis tools allow us to obtain data in inaccessible positions for the experimentations. In this paper, a two dimensional numerical study of steady, static pressure distribution and incompressible flow characteristics inside the passage with different numbers of blades of centrifugal pump impeller has been carried out. The investigation focuses mainly on the efficiency of the pump. Centrifugal pumps with impeller blades 5, 6 and 7 have been modeled and its efficiency at 3000 rpm is evaluated by FLUENT 6.3 software. The numerical analysis displays that with the increase of blade number, the head and static pressure of the Model increases, but the efficiency of centrifugal pump varies with number of blades and shows maximum for 7 number of blade.