Took the weans a walk away up the back of The Three Towns in Ayrshire where they are installing these big bad boys.

  • GreyShack@lemmy.world
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    1 year ago

    They disrupt the trailing edge eddies - which is what causes any noise - and so make them quieter. They are often fitted in areas where sound might be a particular issue.

    • kev@mcr.town
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      1 year ago

      I can’t hear the word eddies without thinking Hitchhiker’s Guide

      “Eddies,” said Ford, “in the space-time continuum.”

      “Ah,” nodded Arthur, “is he. Is he.”

    • Trail@kbin.social
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      1 year ago

      So why don’t my CPU/case fans have serrated edges as well? Because they are too small?

    • Finnbot@lemmy.worldOP
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      1 year ago

      They are surrounding a farm with hunners of cows in multiple fields, so I wonder if the noise is quite scary for them, hence efforts to make them quieter. Or the farmer insisting. Are they usually quite loud?

    • Gormolius@lemmy.one
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      1 year ago

      Trailing edge you say? So not designed to mince up birds, that’s a relief.

        • GreyShack@lemmy.world
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          1 year ago

          Most of the bird deaths are not actually physical strikes - it is a result of the massive change of air pressure as the blades pass at speed. Evidently painting one of the blades black - or some contrasting colour - keeps a lot of the birds well away.

            • GreyShack@lemmy.world
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              1 year ago

              I realise that I had mis-remembered this. It is primarily bat deaths that are caused by the air pressure changes around turbines - not birds. This is because bats have a particularly large and thin lung internal membranes which gives them high efficiency. The rapid decompression in the immediate wake of the turbine blades - particularly towards the tips, which are the fastest moving part of course - damages this membrane.

              Birds have more compact lungs and hollow bones which aid in their breathing - a different solution to the efficiency problem and one that is not as susceptible to these pressure changes.