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Tracy,
The reason I ask is that I like to keep the muffler
outlet the same area size or a little bigger than the exhaust outlet in the
rotor housing which is usually about 2" dia.
I do understand the 2 and 3 rotors are staged and
the exhaust and the exhaust (shock) waves are in sequence, but I like
to keep the volume of the muffler and muffler exit to the total of the rotor
exits i.e. 3x Pi.r squared (3x Pi 1 x 1) = 9.2 sq" or Radius of 1.71" = Dia of
3.42".
I thought 2.25 may have a little too much back
pressure, as the rotary doesn't like back pressure.
Probably to do this exercise properly would be to
calculate the volume of the heated and expanded exhaust gases and calculate the
timing of the pulses to see how a particular sized muffler and exit size coped
with the speed and volume of flow. It would be an interesting
exercise.
George (down under)
Too
soon to say really. I have not even had time to assemble the builders
log to get ready for the DAR. Lack of engine power is definitely not what is
keeping this thing grounded though : )
Tracy
On Sun, May 17, 2009 at 6:01 PM, George Lendich <lendich@aanet.com.au>
wrote:
Tracy,
Any significant back pressure to speak
of?
George (down under)
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Original Message -----
Sent:
Monday, May 18, 2009 12:11 AM
Subject:
[FlyRotary] Re: 20b Exhaust
In general, the bigger the exit pipe, the louder the
exhaust will be. I used 2.25" which I think is about the minimum for
a 20B.
Tracy
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