| Re: Faster than the breeze, dead downwind
[Re: KevinRejda]
#231749 05/01/11 03:43 AM 05/01/11 03:43 AM |
Joined: Feb 2005 Posts: 1,382 Essex, UK Jalani
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Posts: 1,382 Essex, UK | That's been around for quite a while Kevin - and I think it's also been on here before. Unfortunately, not really applicable to sailboats is it? Clever use of technology though - and semantics! 
John Alani ___________ Stealth F16s GBR527 and GBR538 | | | Re: Faster than the breeze, dead downwind
[Re: Jalani]
#231761 05/01/11 10:01 PM 05/01/11 10:01 PM |
Joined: May 2007 Posts: 127 Rock Hill,SC KevinRejda OP
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Joined: May 2007
Posts: 127 Rock Hill,SC | Applicable?, racing, of course not; cruising, I don't know, maybe. Could it work with a prop instead of wheels? The physics is certainly interesting and fairly well explained though. Jake? Wouter?
Kevin Rejda Rock Hill, SC
| | | Re: Faster than the breeze, dead downwind
[Re: KevinRejda]
#231769 05/02/11 05:42 AM 05/02/11 05:42 AM |
Joined: Jun 2001 Posts: 12,310 South Carolina Jake
Carpal Tunnel
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Carpal Tunnel
Joined: Jun 2001
Posts: 12,310 South Carolina | Applicable?, racing, of course not; cruising, I don't know, maybe. Could it work with a prop instead of wheels? The physics is certainly interesting and fairly well explained though. Jake? Wouter? We did go through this at length and it is a bit of a brain teaser. Bottom line; as long as the drag of the vehicle is less than the energy that can be extracted from the moving air, it can exceed wind speed. We do actually do it on catamarans although it's not DDW because we have to keep some angle on our fixed sails to generate efficient lift. there is a fella that designed a boat that has a big air driven propeller on the back and a prop in the water - he can drive the boat DDW and you might call it "sailing". It was a jonboat looking thing so I'm not sure if he could exceed windspeed - but he could travel in any direction relative to the wind.
Jake Kohl | | | Re: Faster than the breeze, dead downwind
[Re: Jake]
#231793 05/02/11 03:41 PM 05/02/11 03:41 PM |
Joined: Jun 2001 Posts: 733 Home is where the harness is..... Will_R
old hand
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Posts: 733 Home is where the harness is..... | We did go through this at length and it is a bit of a brain teaser. Bottom line; as long as the drag of the vehicle is less than the energy that can be extracted from the moving air, it can exceed wind speed. We do actually do it on catamarans although it's not DDW because we have to keep some angle on our fixed sails to generate efficient lift. +1
Last edited by Will_R; 05/02/11 03:42 PM.
| | | Re: Faster than the breeze, dead downwind
[Re: Dan_Delave]
#231913 05/04/11 03:01 PM 05/04/11 03:01 PM |
Joined: Dec 2001 Posts: 5,590 Naples, FL waterbug_wpb
Carpal Tunnel
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Carpal Tunnel
Joined: Dec 2001
Posts: 5,590 Naples, FL | nice video on that linked site. I wonder if having a blade pitch control could help increase the top speed by reducing drag on the windmill?
Jay
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