
About a week ago, I came across an intriguing article on telegraph.co.uk, entitled, “Ocean currents can power the world, say scientists.” Such a title is an immediate eyebrow-raiser for me, knowing the propensity of the news media to (a) overhype scientific results to the point of absurdity, and (b) fall for lots of suspicious “free energy” claims (see, for instance, Bob Park’s excellent book, Voodoo Science). The work reported on here, though, undertaken by researchers in the Department of Naval Architecture and Marine Engineering at the University of Michigan, is based on legitimate science, and was recently published in the Journal of Offshore Mechanics and Arctic Engineering.
The researchers have developed a new device which can effectively extract energy from ocean and river currents, even at low flow rates. The technique, dubbed VIVACE (Vortex Induced Vibration Aquatic Clean Energy), takes advantage of a physical phenomenon known as vortex induced vibration (VIV) to drive the motion of a cylinder. This energy of motion is then converted to usable electric energy.
The phenomenon of VIV, its history, and its possible use as an environmentally-friendly and cheap energy source are discussed below.
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