Now you can see infrasound!

A group of mechanical engineers at the University of Minnesota recently managed to record infrasound visually. By placing a search light next to a wind turbine, with falling snow acting as a screen, it is possible to SEE the footprints of infrasound generated by each turbine blade as it passes in front of the tower. The pulsations are recorded, like footsteps in the snow.

Particle Image Velocimetry is a technique to measure turbulence long used in wind tunnels for small scale testing. Using this technique to measure turbulence in the field on full-scale structures has proved to be very difficult and has been thought by some to be impossible. In February 2013, Eolos researchers demonstrated the ability to visualize large scale turbulent structures using natural snowfall. This allows you to see what for years the industry has denied.


About Dougal Quixote

Slightly mad. Always believes a cup is half full so continues to tilt at Wind Turbines and the politicians that seem to believe it is their god given right to ruin Scotland for a pot of fool's gold.
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6 Responses to Now you can see infrasound!

  1. cornwallwindwatch says:

    Reblogged this on Cornwall Wind Watch and commented:
    and posting again just because this is so important.

  2. henk daalder says:

    Very nice video
    But “the industry” has never denied that this is happerning.
    The issue anti wind propagandists bring up, is whether this turbulence is harmful for persons or not, and up to what distance from the turbine.

    The same infrasound (with less regular pattern) is produced for ages by buidlings, trees and some rock formations.
    Airplanes make excaxtly the same type of infra sound, since planes took off, 100 years ago.

    So, for ages, people have lived in this type of sound, without getting hurt, or being influenced.
    Millions have worked ar miller, in a wind mill, but there is no miller syndrome known, because
    this type of infrasound is not harmfull, Luckyly.

    • Many in the industry at local level have denied it. Does it harm people? That is a point of contention. There is little doubt that some people are more susceptible to low frequency noises and some that causes insomnia and the related problems of stress. Millers don’t live with continuous noise as they only have the blades turning when they are working. Outside that time, at night for example, they furl the sails. Also you can work with noise without problems because you are in control and therefore no stress. Infrasound has been used by the military for years but the problem they have is that it affects some and not others, so as a weapon it is pretty useless. For years people have lived with noise by trains and airports or near heavy industry. Truth is that, as proved by Dr. Chris Hanning, levels of sleep deprivation and stress related illness are far more prevalent in such areas. But, of course, that is not limited to infra-sound. Only recently have we started measuring it and the facility to do that out in the field is still very limited. Therefore to say no one has been hurt or influenced is simply too simplistic. We still don’t really know enough. What the anti wind groups say is that the precautionary principle, enshrined in European and UK law, should be accepted until such time as proper independent research has ascertained the worst case scenarios of infra-sound created by wind turbines.

  3. Low Frequency Noise and Health A wind Turbine Case (2007-2013)
    Mariana Alves-Pereira, Ph. D. Lusofona University Lisbon Portugal

  4. Isn’t that interesting Dougal.

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