This week's Sunday Times Page 5 has an article about an attempt to break the unpowered water speed record.
"Carbon fibre wing sail amplifies wind, making boat travel faster than the wind speed".
If anybody can be bothered to write to the Times explaining how boats with sails made out of my old tee shirts can also travel faster than the wind, then feel free to do so. (Why not ask them if they would pay you to review their Science Articles as well?)
5 comments:
Hm? It is possible (and has been demonstrated) to have only-wind-powered faster-than-wind travel, put takes special conditions and something like a propeller. Is a copy or transcript of the article available online somewhere?
http://en.wikipedia.org/wiki/Sailing_faster_than_the_wind
Well, sailing boats have the ability to travel faster than the wind. The sail forms an airfoil.. Just google it... :-)
The difficult bit is faster than the wind directly downwind.
Thanks for the blog.
You might like these:-
Radio-controlled model Glider that can *sustain* 498mph in non-descending flight. As long as the wind blows in fact.
http://www.rcspeeds.com/aircraftspeeds.aspx?rpt=LL
This video includes 468mph flight
http://www.youtube.com/watch?feature=iv&v=rfoxjNg-eg0&annotation_id=annotation_508371&src_vid=ByOB4luuvy4
It's called dynamic soaring and is used by albatrosses to make effortless transoceanic flights. I barely believe it but am convinced it is all true.
Dynamic soaring explanations.
You will have to seek out your own favourite on the net since different people will like different explanations. there are many.
http://douglasturner.tripod.com/id27.htm
http://www.charlesriverrc.org/articles/flying/markdrela_ds.htm
Section - How and Why Does Dynamic Soaring (DS) Work?
US Air Force Test Pilot School academic paper
http://www.dtic.mil/cgi-bin/GetTRDoc?AD=ADA461327
This makes it clear that yachts (ice or otherwise) can exceed the wind speed in terms of ground covered downwind. i.e. beat a drifting baloon.
http://www.nalsa.org/Articles/Cetus/Iceboat%20Sailing%20Performance-Cetus.pdf
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