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Railrider?

Posted: Mon Sep 18, 2006 8:14 am
by Teeeman
We have a circular sail (vs flat) and it is great for not losing power when the input angle is less than straight on… but in turn also delivers a nice yaw torque (steers our boat) when the angle is not straight on.

Anybody experimented with flat vs circular sails before?

With our boat most likely steering, we will definitely hit the sides and probably stay there.
I am hopeful this will serve as a “rail-rider” and not come to screeching halt on us…

might even dab some light silicone grease on the sides of the boat…


… has anybody made a “rail-rider” Regatta before?



-Terry

Re: Railrider?

Posted: Wed Sep 20, 2006 12:54 am
by Stan Pope
Here are questions that will lead you directly to the answer:

1. What produces adhesion between two wet surfaces?

2. If one surface is near vertical, what shape (vertical profile) produces the least adhesion?

Re: Railrider?

Posted: Wed Sep 20, 2006 9:15 am
by Teeeman
water surface tension?


and minimal contact area (i.e. a blade)...




We put on a VERY thin slime coat of silicone, no gains I could tell, rail-riding isn't a big thing in testing... the boats aren't near so wild as I had fearfully envisioned...


there is also boundary layer effect (what we were shooting for with the slime coat, in addtion to lubrication between surfaces should they meet)


Am I on the right tracks?


-Terry

Re: Railrider?

Posted: Wed Sep 20, 2006 10:00 am
by Down-N-Flames
How about a curb feeler? No chrome needed, but a toothpick off the front and rear would provide the least friction on the side I would think. You need to do both sides of course as you don't know what side of the track you will be on. Not sure the race will be that close based on last year.

Woody