Levrek, leveraging 3D printing for nautical applications » 3dpbm
DMEC researchers have developed innovative solutions for the production of aluminum alloy components with biomimetic surfaces inspired by bar scales. The Levrek Projectt (bass in Turkish) aims to recreate the scales of the bass on the bulb of the rudder of the sailboat Polimi Sailing Team.
The Levrek project seeks to improve the structural characteristics of the component, reducing its weight using additive manufacturing techniques and, at the same time, improving its fluid dynamics characteristics by working on the texture of its surface. Researchers modeled the natural characteristics of fish in a digital environment, performed parametric analyzes using a computational fluid dynamics (CFD) approach to assess their performance, and choose the most efficient proportions of fish scales.
After undergoing topology optimization, the metal scales were produced by laser powder bed fusion (L-PBF) and applied to a rudder bulb. This research is perfectly in line with the objectives of the excellence departments of the LIS4.0 project, where the emphasis is on lightweight and intelligent structures. The research required a multidisciplinary team consisting of sailing, CFD and AM experts. Alessandro Scarpellini, the leader of the Polimi sailing team worked with Dr. Paolo Schito and Professor Ali Gökhan Demir. For the innovative design, an initial study was carried out on the hydrodynamics of bar scales, identifying the optimum scale size to reduce the fluid dynamic resistance of the rudder bulb.
First, the researchers modeled fish scales in a CAD environment: this identified different sizes of scales to be tested in the CFD environment using the open source framework OpenFOAM on the CFDHub framework. High-Performance Computer (HPC).
In addition to identifying the ideal dimensions, the researchers determined the influence of surface roughness and boat speed. Subsequently, they focused on the manufacture of the component: the additive manufacturing process chosen was SLM and the material used was the AlSi7Mg0.6 alloy. The rudder bulb was then topologically optimized to reduce component weight. The chosen fish scale was integrated into the surface of the bulb. The component was fabricated using a Trumpf TruPrint 3000 printer at AddMe.Lab. The result is a one-of-a-kind rudder bulb – a topologically optimized metal component that incorporates bio-inspired surfaces.
The results of this research could pave the way for new naval applications to improve the performance of ships at sea while lightening their components. After careful consideration, they were published in a scientific journal. Thanks to its innovative nature, the work carried out was also appreciated by the world of industry, which decided to reward Alessandro Scarpellini: the young team leader won the UCIMU thesis prize for Italian manufacturers of machine tools, robots , automation systems and auxiliary products. .