SHAPE OPTIMIZATION OF THE ERCOFTAC CENTRIFUGAL PUMP IMPELLER USING OPEN-SOURCE SOFTWARE

Centrifugal pumps are largely used in several fields and for different applications. Despite their wide diffusion, they are often not optimized for working at the design conditions. The aim of this paper is to investigate the potentialities offered by surrogate-based optimization techniques in centrifugal pump impeller shape definition using open-souce software, so as to obtain a robust and fast algorithm for design improvement. The geometry chosen for validating the proposed method is the ERCOFTAC centrifugal pump where accurate measurements and simulations are available in the literature. The three-dimensional geometry of the impeller is described by means of parametric Bezier surfaces, while the flowfield through the impeller is predicted by computational fluid dynamics. The surrogate-based optimization method here described maximizes the pump hydraulic efficiency while keeping the total pressure rise prescribed to the design condition, in order to find the optimal impeller design. The whole optimization chain is designed for running in HPC environment with open-source software. The results of this study demonstrate that a considerable improvement of pump performance is possible through surrogate-based optimization.