Message-ID: <3F6F0045.FD8AB01C@frontiernet.net>
Date: Mon, 22 Sep 2003 09:59:33 -0400
From: Jim Sower <canarder@frontiernet.net>
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To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Subject: Re: [FlyRotary] Re: DIE Power Calculations
References: <list-2588886@logan.com>
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Ed,
It's counter intuitive as all hell.  Took me a long time to accept it, and very
few people who don't flail around in the stratosphere know about that.  If you
were to look at a plot of atmospheric temperature against altitude, you'd see
that temperature decays at the adiabatic lapse rate from the surface to the
tropopause (about 36k', standard day) at which point it stabilizes at something
around -45F for the next dozen miles or so.  Speed of sound stabilizes in the
stratosphere at about 450 kts.

>From my catalog of "Little Known Facts About Unknown People" .... Jim S.
--
Jim Sower
Crossville, TN; Chapter 5
Long-EZ N83RT, Velocity N4095T


Ed Anderson wrote:
Ok, Jim

>
> Must have been asleep in that part of class.  I knew that in the atmosphere
> the density is dependent on the air temperature and the speed of sound is as
> well.  I guess I am still somewhat surpised that if you pressurized a gas
> say to 10-20 atmospheres that speed of sound would not be increased (even
> after you let it cool off from the compression heating).  But, you live and
> learn every day.
>
> I agree that having the intercooler before the throttle body would eliminate
> it from any possible disruption of the DIE FAW.  Also agree that anything
> you do to stabilize intake manifold air temp would also stabilize the rpm at
> which DIE occurs.
>
> Thanks Jim, I stand corrected.
>
> Ed
>
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