Energy boost from vortices: bull trout
Bodies of fish decrease energy required for locomotion by using vortices.
|Biomimetic Application Ideas|
> Visit strategy page
"Aquatic animals swimming in isolation and in groups are known to extract energy from the vortices in environmental flows, significantly reducing muscle activity required for locomotion. A model for the vortex dynamics associated with this phenomenon is developed, showing that the energy extraction mechanism can be described by simple criteria governing the kinematics of the vortices relative to the body in the flow. In this way, we need not make direct appeal to the fluid dynamics, which can be more difficult to evaluate than the kinematics. Examples of these principles as exhibited in swimming fish and existing energy conversion devices are described. A benefit of the developed framework is that the potentially infinite-dimensional parameter space of the fluid–structure interaction is reduced to a maximum of eight combinations of three parameters. The model may potentially aid in the design and evaluation of unsteady aero- and hydrodynamic energy conversion systems that surpass the Betz efficiency limit of steady fluid dynamic energy conversion systems." (Dabiri 2007:L1)
"Fishes moving through turbulent flows or in formation are regularly exposed to vortices. Although animals living in fluid environments commonly capture energy from vortices, experimental data on the hydrodynamics and neural control of interactions between fish and vortices are lacking. We used quantitative flow visualization and electromyography to show that trout will adopt a novel mode of locomotion to slalom in between experimentally generated vortices by activating only their anterior axial muscles. Reduced muscle activity during vortex exploitation compared with the activity of fishes engaged in undulatory swimming suggests a decrease in the cost of locomotion and provides a mechanism to understand the patterns of fish distributions in schools and riverine environments." (Liao et al. 2003:1566)
Note: Studies were on trout, not specifically bull trout.
Salvelinus confluentus (Suckley, 1859)
Some organism data provided by: FishBase
Organism/taxonomy data provided by:
Species 2000 & ITIS Catalogue of Life: 2008 Annual Checklist
Application Ideas: Wind turbines that work using eddies around large buildings or other large structures. Ocean energy devices that use eddies to generate energy.
Industrial Sector(s) interested in this strategy: Construction, energyFLOWE wind farm design - Wind farm spatial design
Vortex Generator - Water treatment systems
Noel Michele Holbrook George V. Lauder
Caltech (California Institute of Technology)