Body shape reduces friction: dolphin

1 of 1 Bottlenose dolphin / NASA / License

The body of the dolphin has low friction in water by having an optimal length to diameter ratio.

Biomimicry Taxonomy

	Maintain physical integrity >
	Manage structural forces >
	Turbulence

Biomimetic Application Ideas

Increasing efficiency of air, ground, and water transportation by decreasing friction.

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[Collapse all sections] Summary

"The streamlined body of optimal shape has a length of 4.5 times its diameter. In this case the surface is smallest relative to the volume. This optimal numerical proportion has not remained a secret from nature: for dolphins (Tursiops gilli) the ratio is close to 5." The author goes on to talk about the Reynolds number and how the shape of the dolphin shows high efficiency: "As a matter of fact, the maximal diameter of the dolphin is slightly back of center. Obviously, the above-mentioned effect was taken into consideration. Experiments have confirmed that this particular shape lowers friction drag in turbulent boundary layers to 65%." (Tributsch 1984: 48)

About the inspiring organism

bottlenose dolphin
Tursiops truncatus (Montagu, 1821)
[bottlenosed dolphin]

IUCN Red List Status: Least Concern
Habitat(s): Marine Coastal/Supratidal, Marine Neritic, Marine Oceanic, Wetlands

Some organism data provided by: ITIS: The Integrated Taxonomic Information System
Organism/taxonomy data provided by:
Species 2000 & ITIS Catalogue of Life: 2008 Annual Checklist

Bioinspired products and application ideas

Application Ideas: Increasing efficiency of air, ground, and water transportation by decreasing friction.

Industrial Sector(s) interested in this strategy: Transportation

Lunocet - Underwater swimming aid

References

Tributsch, H. 1984. How life learned to live. Cambridge, MA: The MIT Press. 218 p.