Hydraulic design of a multiphase rotodynamic pump impeller and test verification

Concerned with the hydraulic design of a high specific speed rotodynamic pump impeller for gas-liquid two-phase flow transportation, a combined approach of inverse method and CFD analysis is presented. The two-phase mixture is treated as a pseudo single-phase homogeneous fluid under the design condition, and the geometry of impeller blades is designed for a specified velocity torque distribution on S₁ stream surfaces through iterative computations of S₁ and S_2m stream surfaces. To obtain a favorable pressure distribution and optimize the flow field, the design specifications and parameters are improved based on the 3-D turbulent flow analysis of the pump impeller using the SIMPLEC algorithm. Experimental results demonstrate that the designed pump has an optimum hydraulic efficiency of 44.0% and it can work in a wide range of flow rate and gas volume fraction without the gas blocking phenomenon. The validity and reliability of the present approach is proved.