Vortex induced vibrations - what is VIV?
Vortex induced vibrations (VIV) doesn't sound very snappy, in fact it sounds completely made up but it isn't, what is it? VIV has been the destructive phenomenon behind most bridges collapsing pre-1980's but it is also the same phenomenon that allows fish to swim as fast as they do. They are the motions induced on bodies interacting with a flow of fluid, such as fish swimming through water. These vortexes will occur around the bases of bridges and offshore oil rigs which is the main reason for fatigue damage due to the consistent nature of the vibrations caused by the vortexes.
It isn't all bad news though, much like using underwater currents to that are slow but consistent to turn kite generators, VIV have recently been seen as less destructive but more like a potential future energy source. Harnessing the slow vortexes, which move at 2 knots rather than 6-8 knots like tidal power, is being researched in the hydropower sector as it will both reduce damage to structures but also give localised energy. How does it work? By using small cylinders that move oscillate with the VIV's they move magnets along a coil producing a mechanical current in what the designers are calling a hydrokinetic power generating device. This current is then passed through to either an energy storage device or used instantly to power a local grid.
To learn more about vortex hydro energy visit the designers website here.
