This paper presents a modified NSGA-II algorithm based on the spatial density (SD) operator, combined with computer graphics-based surface parameterisation methods and computational fluid dynamics (CFD) simulations. This was done to optimise the multi-objective aerodynamic design of a centrifugal impeller for a 100-kW vehicle-mounted fuel cell and improve the multi-conditions aerodynamic performance of the centrifugal impeller of the vehicle-mounted fuel cell (FC). The optimisation objectives are to maximise the isentropic efficiency of the rated and common operating conditions. The optimisation results showed that the efficiency of rated working conditions had an increase of 1.29%, mass flow increase of 8.8%, pressure ratio increase of 0.74% and comprehensive margin increase of 6.2%. The efficiency of common working conditions had an increase of 1.2%, mass flow increase of 9.1%, pressure ratio increase of 0.24% and comprehensive margin increase of 10%. The optimisation effect is obvious under the premise of satisfying the constraints, which proves the optimisation method’s engineering effectiveness and provides technical support and methodological research for the multi-objective aerodynamic design optimisation of centrifugal impellers for vehicle-mounted FCs.

Successful continuous fiber-reinforced composite filament 3D printing hinges on the synergistic relationship between the printing nozzle and precisely controlled process parameters. This research uses a simulation model to investigate how printing temperature, printing speed, and nozzle length affect the prepreg filament’s molten state during 3D printing. We employed the Box–Behnken response surface methodology to optimize these key parameters. Using continuous fiber-reinforced composite filament polylactic acid (CFRCF/PLA) as an example, and a printing nozzle with a 1 mm diameter and an 8 mm length of heating zone were designed. The optimal printing parameters were determined to be as follows: printing temperature of 220 °C, printing speed of 300 mm/min, and printing layer height of 0.2 mm. Experimental validation using the optimized nozzle and parameters demonstrated enhanced stability in continuous fiber prepreg filament printing.

The aerodynamic performance improvement of radial impellers is of positive significance to improve the overall performance of hydrogen fuel cell systems (FCS). Our team proposes a multi-degree-of-freedom (MDOF) surface parameterization method for the global automatic optimization of radial impeller aerodynamics. The MDOF surface parameterization is characterized by fewer variables, construction ease, smoothness, good flexibility, and blade strength maintenance. In this paper, a radial impeller for a 100-kW fuel cell stack is optimized, showing the isentropic efficiency increase of 0.7%, the flow rate increase of 3.77%, and the total pressure ratio increase of 0.37%. The results revealed that the performance of the optimized radial impeller significantly improved, verifying the validity and reliability of the proposed novel design optimization method and providing technical support and methodological research of radial impeller aerodynamic optimization for hydrogen FCS.