Geometric-Energy Methodology for the Preliminary Analysis of an Archimedes Screw Hydroturbine Using 3D CAD

Abstract

Introduction: Archimedes screw hydroturbines are gravity-driven converters suited to low-head sites. A three-dimensional computer-aided design (3D CAD) methodology is proposed for preliminary assessment of the influence of inclination without treating geometric results as validated hydraulic predictions. Methods: Nineteen inclinations were analyzed for a three-flight geometry. CAD provided retained volume, volumetric imbalance, active area, and centroids, which were used to estimate quasi-static torque. An equivalent kinematic closure was used to calculate discharge, rotational speed, and power, and an energy audit was incorporated using the available hydraulic power. Results: The model produced an internal maximum of idealized power of 42.55 kW at 30°, whereas maximum torque occurred at 32.5°. The energy criterion identified non-admissible configurations when the apparent index exceeded unity. Conclusions: The methodology is useful as a geometric-energy screening tool and explicitly delimits the validity domain of simplified assumptions. The 30° result is not a universal optimum; final design requires variable fill level, losses, computational fluid dynamics (CFD), and experimental validation