A DDES-Driven Framework for Hydraulic Radial-Force Reduction in Centrifugal Pumps via Sensitivity Analysis and Surrogate-Based Optimization

Hydraulic radial force from rotor–stator interaction causes pump vibration and bearing wear. To regulate this, this study proposes a low-vibration impeller design framework combining delayed detached-eddy simulation (DDES), Spearman correlation, sensitivity analysis, and multi-objective NSGA-II optimization, while explicitly treating hydraulic radial force as a primary design objective under an unchanged volute configuration, and is supported by multi-condition experiments. Four key parameters are defined: blade wrap angle (φ), governing passage diffusion; outlet blade angle (β), determining exit fluid trajectories; tangential cutting diameter (Dt), controlling shroud radius; and oblique cutting angle (ζ), adjusting near-hub boundaries. Sensitivity analysis indicates that Dt dominantly controls head and force regulation (42.3% head contribution), while β governs efficiency. Multi-objective optimization identifies an optimal low-vibration configuration (φ = 126°, β = 36°, Dt = 136 mm). Under rated conditions, this design curtails mean radial force by 26.6% (from 9.10 to 6.68 N) and blade-passing-frequency amplitude by 11.9%, while efficiency at 0.4Qd increases by 6.75 percentage points. Flow-field analysis demonstrates that force reduction stems from improved circumferential pressure uniformity, jet-wake suppression, and weakened trailing-edge vortical transport near the volute tongue. These results highlight the framework’s design innovation and practical value for low-vibration optimization of centrifugal pumps and related turbomachinery.