Inverse Design of a Centrifugal Pump on the Meridional Plane Using Ball-Spine Algorithm

In this work, an inverse design algorithm called Ball-Spine (BSA) is developed as a quasi-3D method and applied to the meridional plane of a centrifugal pump impeller in an effort to improve its performance. In this method, numerical analyses of viscous flow field in the passage between two blades are coupled with BSA to modify the corresponding hub and shroud geometries. Here, full 3D Navier-Stokes equations are solved within a thin plane of flow instead of solving inviscid, quasi-3D flow equations in the meridional plane. To demonstrate the validity of the present work, the performance of a centrifugal pump is first numerically investigated, and then compared against available experimental data. Defining a target pressure distribution on the hub and shroud surfaces of the flow passage, a new impeller geometry is then obtained in accordance with the modified pressure distribution. The results indicate a good rate of convergence and desirable stability of BSA in the design of rotating flow passages. Overall, the proposed design method resulted in the following major improvements: an increase in static pressure along the streamline, 5% of increase in the pump total head and delay in the onset of flow cavitation inside the impeller.