Friday, January 27, 2012
Humpback Whales Inspire New Ocean Tidal Energy Turbine by Tina Casey
The next generation of ocean tidal energy turbines could be based on humpback whale flippers, and we may have the U.S. Naval Academy to thank for that. The new design is being developed by Ensign Timothy Gruber, who is pursuing a graduate degree at MIT, with guidance from Naval Academy engineering professors. If it proves successful, the new design could give a major boost to efforts by the U.S. Department of Defense to ditch risky, out-of-date fossil fuels in favor of renewable energy.
In contrast to ocean wave turbines, which are powered by relatively dramatic forces, tidal turbines are designed to draw power from low speed flows. On the plus side, tidal turbines are not subject to the hazards and vagaries of wave action. Given the vast tidal resources of the planet, tidal turbines could emerge as a major renewable energy source. The key is in designing high efficiency blades that can extract the most energy from slothful currents.
Drawing from foundational research, the Naval Academy researchers took their cues from Humpback whale flippers and designed a new blade with bumps along the leading edge. The addition of these protuberances has been shown to improve aerodynamic flow, and initial testing at low speeds has borne out the expectations. The researchers also note that the bumps do not appear to interfere with the blades’ efficiency when higher flow rates are introduced.
The Naval Academy blades lend themselves to the kind of large scale tidal turbines that will be needed to generate a significant portion of global energy needs. Humpback whales are just one source of inspiration; for example, a new large-scale underwater turbine based on kite dynamics is also under development. That still leaves plenty of room for micro-turbines and other small scale installations. In the future, there will be slow-speed turbines in rivers and in canals. There may also be turbines that can scavenge for energy in the waters that flow through treatment plants, factories, and other facilities.