Russell Kent wrote:

Hey Paul, on that 3 rotor twin "bizjet" you've been tossing about.  Why
stop at 3 rotors?  :-)  It's like 2 13B's.  I think Paul just recently
built a 269 HP 13B, right?  2 * 269 HP = 538HP.  2* 538HP = 1076 HP for
the whole plane.  That's the magic number, right?  :-)

Russell

Yes over a thousand HP is probably the magic number for
a viable ducted fan airplane.

You might pay a slight penality in power to weight ratio.
There is some evidense however that counter rotating
fans in the same duct are more efficient. In that case
one engine could face forward and the second engine
could face aft. I think Jeff mentioned this in
the Moller Skycar context.

That is only 134 HP per rotor while two three rotors
would be 179 HP per rotor of course.

You now have a four engine airplane so the loss of
one engine would not be such a controlabilty issue.

All and all not a bad idea with a more conservative
approach to rotary engine power density.

Thanks.

BTW  something like this Seastorm rad location might 
would work well for Lance Jaqua's rotary engine biz jet 
configuration. Would help the CG problems and provide cabin 
heat and defrosting for the windshield. There is a low pressure
area where the air spills over and down the fuselage sides
near the lower front corner of the windshield.

We sure cover everthing on here. From carbs to rotary
engine biz jets.

Paul Lamar
 
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