REFLECTOR: Innodyn Engine

[Ron Brown]

This was an interesting note from one of the Canard lists:


Date: Tue, 4 Apr 2006 23:37:50 EDT
   From: CozyCanard at aol.com
Subject: Re: Innodyn engine



In a message dated 4/4/2006 3:46:02 P.M. Central Standard Time,
shpilkus at charter.net writes:

Hi  Bill

We don't know the competence of your A and P, but rather than  criticise
without an engineering or scientific reason, maybe you could  share with us
the concerns of your A and P, such as poor design, bad  bearings, proven
unreliabilty, poor ignition system etc etc etc.

We  might actually learn something then or at least have a jumping off point
to  further discussion.

Bill
Long EZ 289 WD



Bill,

I am a lover/user of APUs (at work).  They are single speed turbines,  at
least in every case I have seen.  We have the T-62 on the EMB-145 in two
versions the T-62T-40C11 and -40C14.  The difference between them is the 
electronics
that control them.  the 11 is an Electronic Sequencing Unit  (ESU) while the
14 is a FADEC.  All automatic ops, they nominally run at  ~103% (ESU) or 
100%
(FADEC) with overspeed shutdown at 108 or 104%  respectively.  They ONLY RUN
at those speeds.  They are not designed  to accelerate or decelerate with a
load, or to be variable speed.  Even the  Garrett TPE-331-14GR/HR-805H that 
I
flew on the Jetstream ran at TWO speeds 72%  and 96-100% RPM (100% was in 
the
35,550 engine RPM range)

That little bugger is single stage compressor and turbine, so not very
efficient.  Compare that to our main engines (Allison nee Rolls-Royce 
AE3007A1 or
A1/1) that have a fan and 14 stages of compression spun  by 5 stages of
turbine spread between two spools.

In the A&P's defense, they are used to dealing with certificated stuff,  and
modification is never taken lightly either buy the guy signing the logbook 
or
by the FAA.  Turbines are simple but take a lot of engineering to  operate
properly/safely/efficiently.

I think that there is more promise in scaling up a model aircraft turbine
for a microjet, turboprops are lagging behind because of the increased
complexity of the gearbox, at least in model size.  The technology is out 
there, but
somebody needs to spend money on it, I don't think ATP/Innodyn is  spending
the money in the right place.  Look at what Williams came up with  in terms 
of
size, that P&W and others are following.  Here are a couple  of links to 
model
airplane turbojet engines:

http://adamone.rchomepage.com/guide7.htm
http://www.robart.com/FunSonic/Turbines.aspx
http://www.jetcatusa.com/  (These folks have a turboprop)
http://www.amtjets.com/

Enjoy,
Jim Hann,  recovering I think.
home for the moment
Cozy MK-IV  #970
KSTL