Wow...
- Thread starter Simon Sexton
- Start date
I've, since that first page, become a convert to this idea. The hardest part of visualizing it is in the video graphics showing a boat pointing straight up wind then turning DDW. It is a simplification of the idea that workers against their point.
As to the speed of the actual river, that is not the point at all.
-Will (Dragonfly)
As to the speed of the actual river, that is not the point at all.
-Will (Dragonfly)
Two things:
1) There is no upwind and downwind. With zero true wind, EVERYTHING is apparent upwind.
2) As to the speed of the river, you need to go re-read my first post. It is VITAL to the model
https://forums.sailboatowners.com/index.php?threads/wow.195114/page-13#post-1514210
It says you liked it. Did you read it??
Last edited:
Experimentation and coolness? 
There is also a rigid wing sail Opti.
Just days before someone puts the two together. You won't need a river as big as the Amazon to test the theory of sailing upstream with no wind.
5 knots current should do it.
-Will (Dragonfly)
There is also a rigid wing sail Opti.
5 knots current should do it.
-Will (Dragonfly)
I know its more like 7 mph max, but I'm rolling with the story! ;^)
Last edited:
so i ask you, can a AC foiler sail ahead with with the apparent wind dead on the nose? i assume not. i could be wrong. if not, case closed
I gave you a like simply because your post lured Jackdaw into the argument! I was wondering how long it would take!Guys can we just agree to disagree? Pleeeaassseee...
Basically, I ran out of arguments against @Davidasailor26, so I finally had to concede and join his party. My gut still tells me not to believe. I'd have to see it to really believe it, I think. 
Simon,Guys can we just agree to disagree? Pleeeaassseee...
It is not a question of agreeing or not. It is a question of being able to understand how this is possible.
Let me throw your quote back at you.
""The problem is not the problem. The problem is your attitude about the problem." ~ Jack Sparrow "
i really respect jackdaw's opinions. all the vector science is what it is, that's easy. the abilities of a wing powering a vessel are new to me. so i asked the question.
this is polite
this is polite
Good one. "Agree to disagree" is just political correctness for: 'we're not getting anywhere so let's make it easy to just give up'. Arguing is only a problem when it becomes a pissing match. I rarely learn anything without a good argument!
Often, I have to repeat an argument before learning anything! But really, all important knowledge is gained only with vigorous argument, I think.
No of course not Jon.so i ask you, can a AC foiler sail ahead with with the apparent wind dead on the nose? i assume not. i could be wrong. if not, case closed
And now I see the point you are trying to make. You are saying in the absence of true wind, the vector angle of the apparent wind will be on the nose. In pure vector math thats true, if you only model WIND.
But the boat will SIDESLIP. and not just as a side effect like a keelboat does, but as a programmed part of the foiling, and (perhaps biggest) the push of the current. That generates the narrow AOA, which is all the foil needs. Remember the wing sail is rigid and actuator controlled and can assume a VERY high AOA, even going above the center-line of the boat.
Last edited:
THAT.
We can agree to disagree about what kind of pizza is best. But not science.
Early one someone said that 'The commentator is playing with numbers a bit'... while I get his point I had to chuckle abit. The commentator in questions is Iain Percy, a 2-time Olympic gold medalist, the tactician on Team Artemis, and one of the world's best foiling sailors. Pretty sure he knows that he's talking about. These teams use closed-loop modeling to test the effects of 1mm changes in foil shape, and test the results on the water with sensors informing the feedback loop. The models are super good now, and I'm pretty sure the model says this happens! ;^)
It's kind of mind blowing. But to paraphrase Jack Sparrow, you have to re-examine how you're looking at the problem, and maybe come at it from the side of 'If we assume its true, what must be true for it to happen'?
you have my attention. one of my other hobbies is RC airplanes. when the wind stops it's a good day for flying. it blends with my sailing addiction. all fixed wing stuff. the glider wings are amazing.
ain't bought in yet, but willing to keep an open mind. will be talking to my pilot buddies.
U of M and their marine tank testing is only 45 miles away. might take a breezer to that school up north and sniff around. could be fun
ain't bought in yet, but willing to keep an open mind. will be talking to my pilot buddies.
U of M and their marine tank testing is only 45 miles away. might take a breezer to that school up north and sniff around. could be fun
Indeed they do. But we're not talking about a theory here, we're talking about a validated model.Theory and fact often differ. I'll believe it when I see it.......... perhaps
In its simplest expression, sailing is converting the energy available due to the relative movement between two mediums (water and air) to movement by the vessel. If there is no relative movement between those two mediums, there is no energy to pull from. A sailboat floating down stream in a ten knot current with a ten knot wind moving with it, won't have any more energy to pull from than a boat sitting becalmed in no current.
-Will (Dragonfly)
-Will (Dragonfly)