Tuesday, August 18, 2015

Y hydrofoils

Mahalo,
as I mention in previous post, the work is done on Y hydrofoil.
It was planed to have finished the foils to TFW at Garda lake,
but was not on priority list :-(

Well I can proudly present the completely new R&D on the Y hydrofoils.
On this project two parallel activities come together. First is I have constructed
and ordered the ALU vertical mold for autoclave technology. This shape can be
used for kite foil vertical or for the Moth boat! Maybe for some future development
on the foiling boats! Game is open. The mold is 1400mm long, tapered from
120 to 100mm with parallel section of 300mm on the top! The the weary first piece
it was made by Albatross-fly company based in region! More about company
here http://www.radolca.si/en/albatross-fly/
and the web page
http://www.albatross-fly.si/proizvodnja.htm#
They are simply the best, we know each other for decades and the foils was made strait
into this "cook pot"


Of course autoclave technology and the result is outstanding.
Big thanks for this suport to Albatros-fly company!

To this vertical I was add the Y hydrofoils! There are at leat two reasons,
one is to avoid the cutting the water surface, the second is to spread the forces
just like V tail on airplanes but in negative direction! Anhedral shape again like
I am using on the tail for kite hydrofoil
http://drlojz.blogspot.com/2015/03/the-internet-galaxy.html

I am sure this set up ca also better handle the flutter on the hydrofoils,
see the post  http://drlojz.blogspot.com/2015/08/wing-flutter-hydrofoils-flutter.html
while the negative V ir Y shape of the wings will spread the forces differently.
So no flutter anymore or at least later at higher speeds!



So if we see this photo on http://sailinganarchy.com/
with the question "what is it?" I am not surprised! Free minds go forward,
it will never stop!


This photos was made on rainy afternoon on local lake Bled, just after the maiden
fly was made. as usual unlucky with the wind, but enough to prove the take off
in 8knots and stable fly. All I can say at the moment, the Y hydrofoil works at
least good as old normal one! more testing and when the weather go better!





  

 So much at the moment!
dr.Lojz



Wing flutter & Hydrofoils flutter

Mahalo,
I was just watching the the US nationals regatta in Moth class and in this video
https://vimeo.com/136467586
at the 04:30 + the whole foil set up come in the flutter
OR
maybe I am wrong and this is just the sampling of the video
(hope yes) otherwise I can only imagine the sound and the vibration :-(

We all know how hard are the Moth foils build, almost unbreakable and
to see the flutter like this O la la! I hope everything was gong well there!



I know flutter is not common on Mach2 boats, here I can not judge if this foils are "home build"
but it is interesting to see!

My answer to this problem are Y foils!





dr.Lojz