Dr. Sami Polatoz
A perfect balance exists between the movements and behavior of a creature, its habitat, and anatomic structure. The sciences try to understand this triple mechanism in every species and put the knowledge they gain to use in developing technology. Research developments in fluid mechanics have revealed the existence of particular mechanisms in the movement of fish in water. Through the sensors they are equipped with, fish perceive surrounding vortices in the water and adjust their position in such a way that they gain extra energy for movement. In 2003 James Liao from Cornell University proved for the first time that schools of fish save energy by benefiting from eddies.1 Another researcher, John Dabiri, has developed a mathematical model for applying this behavior of fish to mechanical systems.2
Conventional water and wind turbines cannot function properly in a whirling current; the working of turbines depends on the existence of a steady and regular flow. In order to be able to obtain energy from vortices, turbines would need to mimic the movements of fish, adjusting their position to the differing angles of flow. A mechanical device to be developed in this respect should perceive the angle of the current flow instantly and adjust itself accordingly.
Normally, wind turbines are set up in high and open places. However, in cities the eddies that are formed by winds moving around buildings and roofs prevent conventional turbines from working efficiently. In order to overcome this challenge, scientists are aiming to develop turbines that benefit from the dynamic principles apparent in the movement of fish, though without imitating the fish exactly. They hope that in this way it will be possible to produce energy from turbulent currents as well. The projects being devised aim to develop different types of turbines to work in air and water. The energy production of these turbines will naturally be relatively low in comparison to common wind turbines operating in strong winds. However, these new types will make it possible to produce energy from winds moving at less than 32 feet per hour, when conventional turbines do not function. So, the total annual energy they are expected to produce will be no less than the regular wind turbines. If scientists can successfully model the admirable engineering applied in the bodies of fish, they will be able to boost the efficiency of these devices dramatically.
- For further information see Liao J. C. et al., “Fish exploiting vortices decrease muscle activity,” Science 302, 1566–1569, 2003.
- Dabiri, J. O., “Renewable fluid dynamic energy derived from aquatic animal location,” Bioinspiration and Biomimetics 2, L1-L3, 2007.