Keel foil section and lateral shape at very low Reynolds numbers

[Guest625101138]

Originally Posted by Doug Lord

Guys ,while the theoretical is very interesting very few people on this planet know what makes an IOM fast like Lester and Graham Bantock do....

*International One Meter-see post #1

Doug
What speed would an IOM be aiming for or typically achieve on the wind?

As a matter of interest, one of the best regarded asymmetrical low Re# foils is the MA409. It is popular for model gliders. It has a thickness of 6.7 or 6.8% depending on the version. JavaFoil correlates well with Selig data for this. I used it for many of my props but getting the slight concavity in the back face is not easy with a hand grinder.

Rick W

[Doug Lord]

Originally Posted by Rick Willoughby

Doug
What speed would an IOM be aiming for or typically achieve on the wind?

As a matter of interest, one of the best regarded asymmetrical low Re# foils is the MA409. It is popular for model gliders. It has a thickness of 6.7 or 6.8% depending on the version. JavaFoil correlates well with Selig data for this. I used it for many of my props but getting the slight concavity in the back face is not easy with a hand grinder.

Rick W

They're faster than 1.34X square root of the wl-say 3 + upwind-top 4-5 knots. Some skinny(non IOM) model monohulls are faster yet. Bantock is the worlds premier builder and one of the top(probably the top) RC model designers and has done a lot of theoretical work including designing a hull for me to use my RC movable ballast system. Completely professional and a first class guy.
My F3 foiler(LOA 55" X 72") did a measured 20 mph in about 17mph wind. It did 12 mph in a 5 mph wind. I digress....

[Guest625101138]

Attached is data for the MA409 foil that JavaFoil produces in a few minutes. Much quicker than waiting for the databook or CD from SOARTECH.

Rick W

[Guest625101138]

Originally Posted by Doug Lord

They're faster than 1.34X square root of the wl-say 3 + upwind-top 4-5 knots. Some skinny(non IOM) model monohulls are faster yet. ......

So very similar to the Re# I am working with on pedal boats and small chord foils.

Rick

[Doug Lord]

Rick I saved the info and am testing here whether I can post a png file. Worked good--thanks for the information!