As I've said before, I am not making that much power. Prop analysis and
fuel burn indicate maybe 120 HP which agrees with Mazda specs. Stock
porting 1986. The potential is there for 180 HP on two rotors, so I'm
waiting for Jerry to get this PPort thing worked out.
As far as the Subaru guy, do I remember correctly that he is not flying
that configuration any more? The VEZ is a 600 lb. airplane while the LEZ
is a 1000 lb. airplane. I think he was turning maybe 3500 RPM and I'm
turning 5500 so his prop was still much larger than mine, around 50
inches I think it was? I'm guessing his plane must have been a runway
hog but it did ok once in the air.
Those goofy antique subarooo piston engines just can't turn up the rpm
like our superior rotary turbines Vance.
Perry

Perry, I also think you can make some drag reductions on your current duct.
The one on the left is your current duct more or less and the one on
the right is lower drag because it is less cone shaped. In other words
the departure angle on the outside surface of the duct is less acute.
Any negative pressure vectors back there will have a high drag components.
Both ducts are designed to have the same inlet areas and the same
out let areas.

Paul Lamar

I agree with your suggestions Paul.
I have been flying with the same duct2/fan3 combo since October 1999
(time sure flies). There were some "failed" experiments with duct3 in
early 2000 but I always went back to duct2 because it's the only one
that really works. It has that expanding rocket nozzle exhaust that
Vance says shouldn't work.
I have some other things on the drawing board that incorporate many of
your suggestions, but I'm not planning on building anymore ducts or fans
until I get that new Renesis PPort motor, which may be awhile yet. It
will require new almost everything - new engine mount, new fanduct
mounting, new intake, new exhaust, new ECU, etc.

Perry

NASA ought to hire you Perry to prove or disprove their ducted fan conclusions.
I brought it up with them last year at OSH but they wiggled out of it. I think
I will bug them again if they show up with that silly Chev V8 engine ducted fan
airplane proposal again. Three or four guys are getting paid big bucks with our
money to sit around and generate fancy Power Point presentation on this half
baked scheme.

BTW you need to write your Congressman about this. NASA would be forced to
investigate this by law if your Congressman forwarded your letter to NASA.

Paul Lamar

They don't care about anything practical or real. They just like to
"study" things. One of the reasons they tout for using a ducted fan is
noise reduction. My plane is very loud, and I think the duct is doing
very little to reduce noise. My son was at the side of the runway when I
did my unducted test and he said it sounded the same as always.

The only thing the duct may be doing is making the noise directional,
probably louder forward and rear and less to the sides.

Perry

 
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