Investigations on inner Structures of the Propeller Blade referring Additive Manufacturing

Abstract

Propeller blades in maritime propulsion systems must withstand complex hydrodynamic loads, torsional stresses, cavitation, and varying static and dynamic pressures, while delivering high thrust, torque, and efficiency. Traditional manufacturing methods (casting and milling) limit designers to solid geometries, precluding the use of advanced hollow or lattice internal structures that reduce weight and material usage. These limitations are overcome by additive manufacturing (AM), especially Wire Arc Additive Manufacturing (WAAM), which makes it possible to produce complex, lightweight designs with integrated internal features in a near- net-shape. In this work, unique internal configurations, derived via topology optimization and biomimetic patterns (honeycomb, gyroid, and bone‑inspired lattices), are investigated for propeller blades operating in diverse environments, from open water to ice‑prone seas. Emphasis is placed on selecting suitable AM materials (e.g., high‑nickel aluminum bronze) and on developing robust WAAM‑milling hybrid processes to ensure consistent bead geometry, material integrity, and compliance with DNV certification guidelines. Finite element analyses validate that optimized internal structures, in which different configurations of internal structures achieve favorable stiffness‑to‑mass ratios while respecting fatigue and strength criteria. This research outlines both design methodologies and manufacturing parameters necessary to realize next‑generation, additively manufactured marine propellers.