Bio-inspired design for impeller and diffuser optimization to enhance the hydraulic performance of slanted axial flow pumps.

This article focuses on a bio-inspired design and multi-objective optimization approach for improving the hydraulic performance, cavitation resistance, and flow deviation of slanted axial-flow pumps. Drawing inspiration from the leading-edge (LE) tubercles of humpback whale fins and the trailing-edge (TE) serrations of Atlantic bluefin tuna finlets, the study redesigns the impeller LE and diffuser TE to enhance pump efficiency and stability. Using computational fluid dynamics (CFD), surrogate modeling with radial basis function neural networks (RBFNN), and the NSGA-III-SSA optimization algorithm, the optimized pump showed up to 7.59% increase in head and 4.33% increase in efficiency under overload conditions, along with a cavitation bubble volume reduction of up to 19.40%. Experimental validation confirmed the numerical results, demonstrating that the serrated diffuser reduces flow separation and vortex-induced energy loss by 16.38%, while the tubercled impeller improves pressure distribution and cavitation performance. This biomimetic design approach offers a promising strategy for enhancing axial-flow pump performance and may be applicable to other fluid machinery.