Inverse Design of Meridional Flow Passage Shape of Centrifugal Pump Impeller Using Ball-Spine Algorithm

In the present work¡ an inverse design algorithm called Ball-Spine (BSA) is developed as a quasi-3D method on the meridional plane of a centrifugal pump impeller with rotating frame and incompressible viscous flow within it¡ with the aim of improving its performance. In this method¡ numerical analysis of viscous flow on a thin plane of flow between two blades using a 3D viscous flow solver is combined with BSA¡ which modifies hub and shroud geometries. Namely¡ instead of solving inviscid quasi-3D flow equations in the meridional plane¡ full 3D Navier-Stokes equations is solved on the thin plane of flow. To show the validity of the present work¡ centrifugal pump is numerically evaluated and numerical results are compared with experimental results¡ and flow field in the meridional plane of pump impeller is obtained using quasi-3D method. By studying the algorithm in the rotating geometry and choosing static pressure and reduced pressure as target parameters the ability of performance of the algorithm is assessed. After that¡ the new impeller geometry is obtained in conformity with the modified pressure distribution¡ by defining target pressure distribution on the hub and shroud surfaces of the conduit and trying to eliminate excess pressure gradients. Obtained results indicate good rate of convergence and desirable stability of BSA in the design of rotating conduits with incompressible viscous fluids. By using the above-mentioned optimization method following results was observed: increase of static pressure along streamline¡ 1% of increase in the pump total head¡ delay in impeller cavitation inception.