Numerical study of effect of the diameter and Number of blades of impeller of down hole submersible oil pump on the pump performance

Centrifugal pumps are widely used in various industries, specially the oil industry. Therefore, investigation of the pattern of flow in the pump and flow behavior arisen from pump geometric variations to optimize design, is of great importance. In this paper, 3D flow in E.S.P. pump which is a centrifugal down hole submersible pump is numerically simulated and the effect of diameter and number of blades of impeller are assessed. Multiple reference frame method is used to model of relative motion of impeller and diffuser and frozen rotor interface is utilized to connect them. The results show that pump head is increased and efficiency is reduced with increase in impeller diameter .Reducing the diameter has a reverse effect. The variations arisen from increase and decrease in diameter are because of the variation in outlet flow angle and increase in frictional losses, respectively. Also, results show that increase in the number of impeller blades cause to increase in head and decrease in efficiency. These variations have happened due to the increased levels of energy transfer to the fluid, as well as increased frictional losses.