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Faster than the wind??

Posted: Sun May 30, 2021 11:56 am
by AlexQ23
A wind vehicule that goes faster than the wind down the wind?? I find this video quite interresting!! Enjoy it!!https://youtu.be/jyQwgBAaBag

Re: Faster than the wind??

Posted: Tue Jun 01, 2021 12:58 pm
by John Perry
The land yacht in that video, 'Blackbird', which Wikipedia tells me was built in 2010, appears to be basically similar to one built by Andrew Bauer many years earlier. Both were able to sail directly downwind substantially faster than the wind speed. As far as I know, Andrew Bauer was the first to demonstrate this with a man-carrying vehicle. I know that at one time Dave Culp sent me a photograph of the vehicle that Andrew Bauer built but I don't seem to be able to find it now, but I do have some papers by Andrew Bauer that I think were sent to me by Dave Culp, one of these is here: There have also been many small scale non-man-carrying models built that work the same way, one is actually on the AYRS YouTube channel at https://www.youtube.com/watch?v=aJpdWHFqHm0.

At one time there was a debate about this among AYRS members which I recall rather dominated the society for several few years - there was a risk that the AYRS would be regarded as just the
'Downwind Faster Than The Wind (DWFTTW) Society!

I always envisaged the concept for a waterborne version as two screws of different pitch linked together as at this link - https://www.hostellerssailingclub.org.u ... ers-part-2 - once you see it that way I think it is rather obvious that the concept is workable and that it is only energy losses that may make it difficult to realise in practice. As far as I know it has never been achieved with a water vehicle, the energy losses may well be too great and to my mind it is hardly worth trying given that some sailing boats tacking downwind can in any case achieve a downwind velocity made good that is significantly greater than the true wind speed.