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Marcus,
I am really glad you brought up the Mistral
incident, as I have been meaning to mention it too.
For what it's worth, my experience with mufflers
confirms what many other have said. The exhaust
environment in rotary aircraft is very extreme and
component failure can be catastrophic. I have
tried several types of high end packing, and nothing
survives more than a few hours. 300 series
stainless tolerates the heat, but any welds on thin
stainless have limited life. I would be very
suspicious of anything with complex innards like the
Aero Turbine 2525. Doing what Jeff Whaley did by
adding perforations should be a must-do in my
opinion.
Dave Leonard
Just remember the Mistral muffler
event. The muffler caused the Piper Arrow (?)
with their rotary to crash after the internals
blocked the outlet and led to power loss. It may
have partially led to their withdrawal from the
engine/PSRU market. To all our loss.
M
Sent from my iPad
This is the
Aero Exhaust 2525XL diagram. I have one,
but left it in Canada. Will bring it
back with me in Jan to try at taming the
exhaust again.
- Matt Boiteau
On
2019-11-19 3:23:50 PM, Charlie England
ceengland7@gmail.com
<flyrotary@lancaironline.net>
wrote:
Kelly,
I would if I had
some, really did not
expect it to work as
I deviated from the
design a bit. Will
be back at airport
on weekend to take
photo, too late for
construction photo.
But nothing to it.
I
read about the
idea by Gary
Schwarz in this
thread, post #7 , post #58
for his testing
and post #142
sums up his
findings.
Someone
on here may know
him as he was
doing it for a
rotary. Mine is
much shorter
than his drawing
below due to
space
constraints but
the theory
works.
edit:
Ahh!!! deleted
his picture as
too big to
post. it is in
his post #7
mentioned
above though.
Andrew
That
looks a lot like a simplified
version (one less turn) of a
standard automotive muffler.
The
Aeroturbine tries to achieve
similar effect (without the
flow reversals) by using
venturi effect to suck part of
the exhaust around and then
back into the central tube.
Charlie
<2525.JPG>
--
Homepage: http://www.flyrotary.com/
Archive and UnSub: http://mail.lancaironline.net:81/lists/flyrotary/List.html
The caution about potential blockage is warranted on any
engine, but obviously a greater danger with the rotary's
powerful pulses.
It's worth mentioning that the Renesis' exhaust should be
significantly less 'violent' than a 13B, for a couple of
reasons. The exhaust has to take a 'sharp right' as it
exits the combustion chamber, which helps break up the
shock wave a bit, but even more importantly, the exhaust
port, instead of 'snapping open' like a piston ported two
stroke, opens more gradually, more like a conventional
poppet valve in a piston engine.
As a FWIW on the Aeroturbine: I don't have a 2525XL to
examine, but the regular 2525 (minus the 1st chamber of
the XL) is a 'straight through' design. That cone on the
input end is open. Drawing of the guts is on the
Aeroturbine web site.
https://aeroexhaust.com/i-30497606-aero-exhaust-turbine-at2525-performance-muffler-2-5-inside-diameter-necks-aggressive-sound.html
IIRC, Tracy's been flying one on the 20B powered RV-8 for
a number of years. That's what motivated me to purchase
one, but it hasn't seen any exhaust gas yet.
Charlie
Charlie,,
Any idea how many hours Tracy has on his
AeroTurbine 2525.............?
--
Kelly Troyer
Dyke Delta_"Eventually"
13B_RD1C_EC2_EM2
I don't, but I believe that it's been flying for a number of years
with that muffler. Hopefully he'll see this thread & give us
some 1st hand info.
Charlie
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