Will
The fuselage is 27.5 inches wide so that is normal for a tandem
cockpit. My shoulders are only 20 inches across and I am not small.
Unless of course you are a really big guy :) The tunnel only needs to
be six inches wide and six inches tall.
I am sure the seat is at least six inches or taller as other wise
the pilot would not be able to see out.
The tunnel will enhance the structural strength. It will decrease
the tendency to buckle. I would also make it out of metal as you will
need some metal down there to protect the composite from exhaust
heat.
The P47 had a large tunnel for air ducting as the turbo charger was
in the aft fuselage.
It is not just power. The fuel burn (BSFC) is lower at the torque
peak. With 18 to 20 inch intakes the torque peak is at 6,000 RPM. If
you intend to cruise the airplane at a lower RPM than the intake
runners should be even longer. That will reduce the top HP. You have
plenty of room for longer runners.
The fuel burn is also a function of the back pressure in the
muffler.
The structural integrity of the universal mount depends on the tubes
converging to a point in space close to the motor plate.
Apparently you are making a trade off for styling. That is something
they used to do in cars :) Now all cars are beginning to look likethe
Toyota Prius because that has the lowest drag factor and gives the
lowest fuel burn. Of course that is your call. I just make
suggestions :)
I am glad that more people are starting to use Rhino. It enhances
our ability to share ideas.
Paul Lamar
Paul,
You hit the nail on the head. The look of this plane was 100%
inspired by what I thought would look good. Basically it's a WAR
Replica aircraft with a composite fuselage (as opposed to wood
frame), and a rotary instead of a 0-200 or comparable. I wanted a
aircraft that was uniquely my own so I picked the planes I liked the
most (Corsair, Spitfire, Mustang, Fw-190) and combined all the style
elements that I liked into one plane. And yes the cowling was most
definitely inspired by looks not practicality but the volume the
radial style cowling offers is it's own practicality. I tried raising
the engine up until the spinner was tangent to a curve that was drawn
from the top of the firewall and looked at component locations. About
the only thing that didn't give me an immediate headache trying to
figure out where it would go is the alternator.
As you can see in the attached screen grab there isn't much room
between the firewall and the main spar (which goes all the way to the
bottom skin). The grey tube is your ejector and there just isn't any
room for it unless I hang it under the plane. It looks a lot bigger
when placing it right up against the rest of the plane. I wear size
13 shoes and having a tunnel go between them although plausible would
make me want to jump out of my skin (I'm slightly claustrophobic) if
I couldn't have any room for my feet side to side. I have built a
mockup of the cockpit if you were wondering.
I moved the exhaust outboard a little and that allowed the center of
the ends of the motor mount tubes to get within about 1" of each
other at the motor mount plate. Hopefully that will be enough. It
does require a bulge on the side of the cowling. Aircraft design is
all about compromises and the bulge is the one I'm most comfortable
with. I can live with it being a little noisier and having a little
higher fuel consumption. In exchange I get a whole lot of space to
put everything and a good looking plane as well. And the bulge will
add a little more Fw-190 to the flavor.
So basically unless there is some major functionality issue that
hasn't been mentioned yet I think my basic course is set.
Will Aldridge
That's a beautiful airplane no doubt about it.
Please send me the 3DM on the pilot.
Paul Lamar
Paul,
It's pretty crude but you're welcome to it. It's roughly a 95% guy.
Maybe about 6'2". I measured myself to make him and broadened the
shoulders and hips a little and made him slightly taller just so I knew
there would be some wiggle room in the cockpit. And he's wearing size
13 shoes.
Will
Thanks. He is about my size with the same shoes :)
I think you might have problems with the muffler. Most people do.
Could you make the fuse a little deeper oval?
The intersection drag with the wing would be less and you could get the
muffler in there.
I'll get my Hoerner Fluid Dynamic drag out and scan it shortly.
Not the whole thing of course.
Paul Lamar
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