|
|
This airplane is at my airport, two rows away in the hangers. He initially
had the NACA duct in the belly, but didn't like upflow through the engine,
so had ducts to take the air to the top and a plenum. Didn't cool
adequately. He then changed to the top NACA ducts, using plans from
Velocity. This was an improvement, but still not adequate. Once he started
measuring pressure drop across the engine, he started making good
improvements. He did a number of tests with and without the 'side rails' as
well as with and without the vortex generators. What he has now works really
well.
He also has exhaust augmenters, which help a bunch on the ground, taxiing,
etc. the bottom cowl has since been redesigned but still has the augmentors.
Bill Schertz
KIS Cruiser # 4045
----- Original Message ----- From: "JJ JOHNSON" <JJJOHNSON@ACCESSCOMM.CA>
To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
Sent: Thursday, November 20, 2003 9:16 AM
Subject: [FlyRotary] Re: Core vs Radistor was Re: [FlyRotary] radiator
Jim, by diffusers do you mean the pic showing the little alum. angle's
that
are [ look like anyway] bonded to the fuse ~12" ahead of the inlet? They
look like vortex generators? I was curious as to what the side 'rails'
are
that are located on each side of the inlet ramp to the duct. If nothing
else they sure look cool. I think one of the major problems w/ the Naca
ducts used in this application is that they should still be placed in an
area of high pressure. I my humble opinion, right behind the thickest part
of the fuse isn't really a high pressure location. However having said
that.. I'm not sure where else he could have put them unless he had
wanted
to do alot of ducting. I think that's why he put those little VG's where
they are. It would appear that he was having problems w/ airflow velocity
[boundary layer thickness] and by adding the vg's he re-energized or speed
up/thinned down the boundary layer and improved the airflow into his
ducts.
I've seen several pictures of Long-Ez's w/ very large Naca ducts on the
bottom of the fuse, which in my mind would be a higher area of pressure
that
on top at least, unless I'm missing something.
My two bits
Jarrett
|
|