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I was curious if you could design a hydrofoil system that actually reduces AOA of the hydrofoil as the aircraft speeds up and the wing of the aircraft begins to take the load
Yes. One simple mechanism of controlling hydrofoil AOA is to deploy a ski ahead of the foil to sense the position of the surface of the water and adjust the AOA using a simple lever system. See the Hobie Trifoiler for an example of this. Having the Hobie system dangling from the bottom of an aircraft would make an excellent candidate for the first, one and only Heath-Robinson heron. Anyway, as the wing starts to lift the plane the ski will sense that the foil is closer to the surface than before and decrease the average foil AOA.

Regards, Max
 

aquavion

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Wow...you guys really run with a subject !!

The Barracuda I referred to was of the fish variety and the "tuck" was as you described Everyman_flight. Those are incredible speeds you quoted for the torpedo...its amazing what you can do to "fool" a projectile into thinking it's moving in air via boundary layer modification !! A similar technique is used to under-water launch an ICBM through a coat of bubbles until it reaches the surface. I wonder how much horsepower is needed to support the boundary layer modification relative to the installed horsepower ? In the case of a rocket this is preumably quite small.

Ray Richards
 

tunnels

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has anyone seen how the foil works under the Hysucat boats !! its made to produce lift and plane on the waters surface between two hull so is a completely different approach to foils way under the water .
I feel people are blinded by the science and not seeing what's already out there that works ! why take something simple and turn I into a complicated nightmare subject ??
 
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tunnels

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ooops again and no answers ! Foils have uses but not applicable to amphibian's I fear !!Long spindly thin legs supporting lots weight and even as small thin foils that have to be and stay fully submerged till the moment of lift off these are the wishes of a crazy person !!
 

akwrencher

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ooops again and no answers ! Foils have uses but not applicable to amphibian's I fear !!Long spindly thin legs supporting lots weight and even as small thin foils that have to be and stay fully submerged till the moment of lift off these are the wishes of a crazy person !!
I suppose these guys must be crazy then ;)

LISA Airplanes - Pleasure aircraft designer
 

tunnels

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they sure are !! now come on be truthful How many planes they sold ? how may planes are in regular service flown by the average Joe on the block ! how many foils did they have to experiment with before they got one pair to stay without breaking bending twisting ! and most important if one foil gets damage is it possible to take off or land on water with just one foil. Id say at a rough guess you would want a bible in one hand and our joy stick in the other , Its pretty plane yes but you'd have to be high to want to buy one !
 

akwrencher

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No idea on any of those questions. Simply pointing out that it can and has been done. Military did a bunch of testing with different foils back in the day, and didn't end up going that route. Must be a reason. Still, like I said, it has been proven to work, ideal or not.
 

tunnels

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Think !! Is there just one type of foil ?? Is there only one size of foil ?? what is the failures of foils ? what advantages do they have? what are there disadvantages ( and they have plenty ) How do you get over and past those problems ??? everything has problems !! right ? why not combine a few things together and take the good points of each and make them work where each disadvantage leaves off and the next idea takes over and works for you !!

Foils and ski's ?? ski's and foils ?? could they be made to work together ? or in combination ??
Box's !! get out of the one your in !!!
 

Topaz

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Think !! Is there just one type of foil ?? Is there only one size of foil ?? what is the failures of foils ? what advantages do they have? what are there disadvantages ( and they have plenty ) How do you get over and past those problems ??? everything has problems !! right ? why not combine a few things together and take the good points of each and make them work where each disadvantage leaves off and the next idea takes over and works for you !!
Even just a little use of the search function here on HBA will turn up most of the answers you seek. The topic has been discussed several times.
 

BJC

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Think !! Is there just one type of foil ?? Is there only one size of foil ?? what is the failures of foils ? what advantages do they have? what are there disadvantages ( and they have plenty ) How do you get over and past those problems ??? everything has problems !! right ? why not combine a few things together and take the good points of each and make them work where each disadvantage leaves off and the next idea takes over and works for you !!

Foils and ski's ?? ski's and foils ?? could they be made to work together ? or in combination ??
Box's !! get out of the one your in !!!
OK, just did.
No.
No.
Varies with design, maintenance and usage.
Some are better.
Some are prone to over-punctuate.
Thinking "outside the box!"
No, not everything.
Because of stupidity.
Done properly, they could.
Rather than get out of the box, I prefer to "take to the next level."


BJC
 

tunnels

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Taking it to the next level is still thinking single mindedly and still being in that box ! dispense with the box !!
Ski's and foil each had advantages over the other now introduce the gull !!wont really work on a foil ! will partially work on a ski but it also has terrible limitations or it would still be used on water ski's!! Sea planes used that shape !! but boat hulls are shocking things with Gull shaped hulls ! so where to from here ??
 

BJC

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Taking it to the next level is still thinking single mindedly and still being in that box ! dispense with the box !!
Ski's and foil each had advantages over the other now introduce the gull !!wont really work on a foil ! will partially work on a ski but it also has terrible limitations or it would still be used on water ski's!! Sea planes used that shape !! but boat hulls are shocking things with Gull shaped hulls ! so where to from here ??
Exclamation Points | Punctuation Rules
 
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