Mechanical and Hydrodynamic Analyses of Helical Strake-like Ridges in a Glass Sponge

Matheus C. Fernandes, Mehdi Saadat, Patrick Cauchy-Dubois, Chikara Inamura, Ted Sirota, Garrett Milliron, Hossein Haj-Hariri, Katia Bertoldi, and James C. Weaver (jweaver@seas.harvard.edu)

View the Project on GitHub matheuscfernandes/sponge-ridges

Follow me on LinkedIn linkedin.com/in/matheuscf

Follow me on ResearchGate researchgate.net/profile/Matheus_Fernandes2

Follow me on Google Scholar scholar.google.com

View some of my other Git projects git.fer.me

Visit my website mcfernandes.com

About the Paper

Abstract

From the discovery of functionally graded laminated composites, to near-structurally optimized diagonally reinforced square lattice structures, the skeletal system of the predominantly deep-sea sponge Euplectella aspergillum, has continued to inspire biologists, materials scientists and mechanical engineers. Building on these previous efforts, in the present study, we develop an integrated finite element and fluid dynamics approach for investigating structure–function relationships in the complex maze-like organization of helical ridges that surround the main skeletal tube of this species. From these investigations, we discover that not only do these ridges provide additional mechanical reinforcement, but perhaps more significantly, provide a critical hydrodynamic benefit by effectively suppressing von Kármán vortex shedding and reducing lift forcing fluctuations over a wide range of biologically relevant flow regimes. By comparing the disordered sponge ridge geometry to other more symmetrical strake-based vortex suppression systems commonly employed in infrastructure applications ranging from antennas to underwater gas and oil pipelines, we find that the unique maze-like ridge organization of E. aspergillum can completely suppress vortex shedding rather than delaying their shedding to a more downstream location, thus highlighting their potential benefit in these engineering contexts.

 

Supporting Material

All supporting videos can be found here: VIDEOS

All supporting information can be found here: SUPPLEMENTARY INFORMATION

If there are additional suggested changes or improvements to the code, please submit a GitHub pull request and email me at (fernandes@seas.harvard.edu).

Supporting Video