Experimental Ducted Fan Aircraft Designs

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dog

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Dec 29, 2019
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=today synchronous permanent magnets motors generate 10 kW/kg !

<98 %...effic.
Agreed,motors are now already good.
But batteries are not so good,so: lighter motor
makes room for heavy battery.
 

dog

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Dec 29, 2019
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276
BUT !=
=rotating motor with rotating propeller(s) can generate <10 kG thrust/kW +noise + safety problems !

=flapping (OSCILLATING) thrusters are as minimum ONE ORDER better,>100kG/kW !!! +lower NOISE +allmost SAFE for enviroment...
Again you are right, flapping is much more efficient.
Missing ingredient is materiels for very light and
very strong wings and fueselage because to exploit flapping phenominon will require electric with heavy batteries.
A problem with flapping wings is that speed will be limited I think, and large > 10 ton-50ton aircraft
will be dificult.For personal transport it will be very
good.
 

henryk

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A problem with flapping wings is that speed will be limited I think, and large > 10 ton-50ton aircraft
=strange "paradox" of Gray=fish needs little power for speed ...
(Zhukovski-Knoller-Betz Effect =weavy flow reduce drag force,leads to ANIHILATION of them and even=Cd < 0 !!!!! )

look dr Sorokodum works= vortexosc.com
 

henryk

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to integrate a faux jet exhaust LED lightshow into the rear of the ducts.
+smoke generator ...

 

Doggzilla

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The problem with existing ducted fans is that the physics calculations are all inherited from jet engines, but they dont work even remotely the same, so the math is garbled.

Well, whats the problem with using Jet physics?

Well, firstly, the main power comes from combustion and not the fan itself.

Secondly, the fans are extremely small compared to the size of the aircraft.

Thirdly, their exhaust is supersonic.

None of which applies to any ducted fan.
 

dog

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this book is for industrial fans from fractional hp
up to thousands of hpIMG_20200323_190809.jpg
all the math IMG_20200323_190955.jpg
 

Doggzilla

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I would be surprised if that included fans that operated at transonic speeds.

I wonder if supersonic air tunnel design may be of use.
 

Doggzilla

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Also, turbine ability to compress air massively increases effective thrust.

In fact, an engine with a 40:1 compression ratio is very close to 4 times as efficient as one with just 10:1 compression.

It will be an SFC of around 0.5 instead of around 2.0.
 

dog

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I would be surprised if that included fans that operated at transonic speeds.

I wonder if supersonic air tunnel design may be of use.
leafed through it a bit and it discusses designing
for "high relitive mach numbers", and the book
has a lot of formulas and a section on "fan laws"
 

Yellowhammer

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Feb 21, 2020
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Use the Ski Doo 900 Ace Turbo snowmobile engine; it is the best suited and very little work needed for an aircraft.

You'll have to install a belt drive reduction to suit the propeller you use and the height of the thrust line; I don't think you'll get a geared redrive to work successfully, it may work, you'll have to do your own homework on that part.

Where are you located.

Sorry for just now responding. I live in Louisiana. About 55 miles north of New Orleans.

I was thinking of a geared re-drive. I have no qualms with belt driven but prefer geared. I wonder if a rotax PRSU would cut it?
 

Yellowhammer

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Feb 21, 2020
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The prices are on their site.

Blackhawk,

I think a counter rotating system a 582 would be sweet. My Pulsar call for a 582 engine. The counter rotating would be cool as long as I could build/install a spinner for it.

Any increase in hp?

Thanks,
Yellowhammer
 
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