Tuesday, May 27, 2014

Hydrofoil 2014 part II

as some request was written on Kiteforum, section Hydrofoil
like @drLihgtWind find the Stelth race board from the past is used
to test new foils creation. Nice comment good observation ;-)

@ windfreak74 was asking for more specifications of the hydrofoil,
lets make some points clear first.

As I wrote already the foil is made out of Moth hydrofoil molds with shorter span of 500mm
and the cord of 110mm. At the hydrofoils we have on the first place two well known problems!
Ventilation and cavitation, as the ventilation occur when the air from above the water line is drawn
and cavitation occurred when the water pressure around the foil come to the point of boiling.
More about this stages here

The reason to have the curved mast to front is to avoid the possible ventilation,
this is one point the second is pointed angle forward  in vertical axis by Yaw movement give us
some positive Pitch movement, not to draw the nose down!

-The tail must to be out of turbulence of the stunt and wings
-Why Inverted V tail? On the whole hydrofoil geometry we need the same flying surfaces as on the airplane.
Wings, tail, rudder! The V-tail is lighter, has less wetted surface area, and thus produces less drag.
Inverted V tail geometry is in this construction well out of the turbulence of wings and body of hydrofoil.

-General length from wing to tail 500-600mm

Some more ideas and work already on the desk and the cad screen,
lets see whats come out of this pot!