In this work, the NSGA-II multi objective genetic algorithm, numerical methods, and parametric design techniques found in the Autodesk Inventor professional 2023 CAD software were combined to perform the geometrical optimization of the Pelton bucket geometry. The validation of the proposed method was carried out with numerical simulations using the OpenFOAM CFD program and taking into account the case study turbine’s operating conditions, as well as the k-SST turbulence model. The CFD simulation results and operational data from the case study turbine from the “Illuchi N°2” hydrocenter have been compared in order to validate the proposed methodology. The implementation of the NSGA-II in the design process resulted in optimized bucket geometrical parameters: bucket length, width, inlet angle, and outlet angle. These parameters not only resulted in a 2.56% increase in hydraulic efficiency, but also led to a 0.1 [kPa] reduction in the maximum pressure at the bottom of the bucket. Further research will involve testing these parameters using 3D printing methods to validate their effectiveness.

The structural integrity and surface quality of parts produced using traditional fused deposition modeling depend on factors such as layer height, filament and build orientation, print speed, nozzle temperature, and, crucially for this study, both planar and non-planar slicing. Recent research on non-planar slicing techniques has shown significant improvements in surface smoothness and mechanical properties. Key approaches include non-planar slicing for 3-axis printers, adaptive slicing to optimize material placement in critical areas, and post-processing. However, current studies lack a comprehensive method for parameterizing filament direction across both planar and non-planar layers. This work presents an approach to generate optimal trajectories for planar and non-planar layers using contours derived from level set functions. The methodology demonstrates the advantages of non-planar printing, particularly with a filament orientation of 30° for inclined surfaces, ensuring better surface quality, uniformity, and structural integrity. This emphasizes the importance of trajectory planning and filament orientation in achieving high-quality prints on inclined geometries. This research highlights the necessity of a methodology that tailors filament paths based on the load-bearing requirements of each part, demonstrating its potential to enhance surface quality and structural performance, and further the advancement of the 3D printing industry.

This study compares the hydraulic performance of two centrifugal-pump impellers operating in pump and pump-as-turbine (PAT) modes: a reverse-engineered impeller obtained from a commercial pump by 3D scanning and an impeller developed through a preliminary analytical sizing procedure. Both configurations were evaluated under the same computational framework using OpenFOAM, the Multiple Reference Frame approach, and the k-omega SST turbulence model. Hydraulic performance was assessed through efficiency, pressure, velocity, and turbulent-dissipation fields, complemented by velocity-triangle and parametric sensitivity analyses. The reverse-engineered impeller achieved efficiencies of 90.50% in pump mode and 67% in PAT mode, compared with 79.17% and 50%, respectively, for the analytically designed impeller. Internal-flow analysis indicated that the reverse-engineered geometry produced more uniform velocity and pressure distributions and less extensive turbulent-dissipation regions. Velocity-triangle analysis indicated that its inlet blade angle increases the incidence mismatch in pump mode but reduces residual tangential velocity in PAT operation, favoring angular-momentum transfer. Sensitivity analysis indicated that the dominant geometric parameters depend on the operating direction. The analytical procedure is therefore interpreted as a preliminary sizing approach rather than a validated dual-mode optimization method. Overall, the results indicate that reversible impeller design should consider both operating directions and subsequent CFD-based refinement.

This study presents a computationally inexpensive preliminary sizing and parametric-design procedure for a centrifugal-pump impeller intended for exploratory operation in pump and turbine modes. A hydraulic loss model was coupled with a real-valued genetic algorithm to screen a restricted design space without embedding CFD simulations in the evolutionary loop. The selected geometry was reconstructed and comparatively assessed with steady RANS simulations in OpenFOAM 12 using the k-omega SST turbulence model. Relative to the reference parametric geometry, CFD results at the prescribed conditions showed efficiency increases of 7.48 percentage points in pump mode and 11.05 percentage points in turbine mode. The results do not validate a dual-mode optimization method or establish performance over an operating range. They show that, within the selected correlations, parameter choices, and passive geometric constraints, a combined geometric modification can improve the numerical response at the investigated conditions. CFD and experimental assessment over complete performance curves are required before broader design claims are made.