Doug Lord
Flight Ready
- Joined
- May 26, 2009
- Messages
- 16,679
- Reaction score
- 353
- Location
- Cocoa, Florida
34th AC on Foils!
Magnus of the Canadian C Class Champions from a post on SA:
I've never really said it publicly till now, cause everyone knows I am "the wing nut" and I get all hot and bothered about wings, but from about 4 seconds after the rule was cast everyone who was anyone knew the design race would be won in the water with foils, not in the air with wings. You only need to look at a few rudimentary VPP graphs to see the difference between foiling and floating to know that you want to fly as much boat as you can, because the drag goes up so fast in float mode and it goes up a lot slower in foiling mode. The big problem is control, because you cannot have actuated surfaces to control ride height you have to figure out how to manage the whole package to keep it on its feet, in a safe enough mode you can put your foot on the pedal.
We went back to traditional for a couple of reasons, the biggest being it didn't work, in our chosen configuration. I am not convinced the C-cat has enough power to make it work well enough at all, at least for Fredo and I cause of how we like to sail the boat downhill. The 72's can unfurl a nice big code zero and that offers a lot of power to get up on the foils efficiently, now the trick is to ride a bike with no handlebars so to speak. Foiling without automatic ride height control really is, "Look ma no hands!".
My guess is the focus on foiling will be downhill as upwind they may have to trade away too much righting moment to make it worth it. I haven't seen any real numbers recently so it's difficult for me to say either way. For righting moment remember that your foil as it kicks in essentially moves the center of floatation of the hull towards the middle of the foil. When 100% up on a foil the boat is rotating around a point between the middle of the upright foil and the horizontal foil, well below and inside the center of actual bouyancy. As such you lose some leverage and therefore lose righting moment so you can apply a bit less power, so the trade off needs to be worth it to go for it.
So yes, my vote is anybody who is serious will be foiling, as soon as they are going downhill.
PS, I wager the big white tubes are inflatable structures.
I cut it twice and it's still too short
Magnus of the Canadian C Class Champions from a post on SA:
I've never really said it publicly till now, cause everyone knows I am "the wing nut" and I get all hot and bothered about wings, but from about 4 seconds after the rule was cast everyone who was anyone knew the design race would be won in the water with foils, not in the air with wings. You only need to look at a few rudimentary VPP graphs to see the difference between foiling and floating to know that you want to fly as much boat as you can, because the drag goes up so fast in float mode and it goes up a lot slower in foiling mode. The big problem is control, because you cannot have actuated surfaces to control ride height you have to figure out how to manage the whole package to keep it on its feet, in a safe enough mode you can put your foot on the pedal.
We went back to traditional for a couple of reasons, the biggest being it didn't work, in our chosen configuration. I am not convinced the C-cat has enough power to make it work well enough at all, at least for Fredo and I cause of how we like to sail the boat downhill. The 72's can unfurl a nice big code zero and that offers a lot of power to get up on the foils efficiently, now the trick is to ride a bike with no handlebars so to speak. Foiling without automatic ride height control really is, "Look ma no hands!".
My guess is the focus on foiling will be downhill as upwind they may have to trade away too much righting moment to make it worth it. I haven't seen any real numbers recently so it's difficult for me to say either way. For righting moment remember that your foil as it kicks in essentially moves the center of floatation of the hull towards the middle of the foil. When 100% up on a foil the boat is rotating around a point between the middle of the upright foil and the horizontal foil, well below and inside the center of actual bouyancy. As such you lose some leverage and therefore lose righting moment so you can apply a bit less power, so the trade off needs to be worth it to go for it.
So yes, my vote is anybody who is serious will be foiling, as soon as they are going downhill.
PS, I wager the big white tubes are inflatable structures.
I cut it twice and it's still too short
