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Re: re Re: Ceramic coating EM's - II



Kirby,

Your approach addresses the entire energy balance of the "closed system."
Energy in = exhaust gas in + intake air in.  Energy out = exhaust gas out +
intake air out + heat rejected from the turbo casing.  Yes, the intake air
coming into the compressor has some energy.

Since , energy in = energy out; exhaust gas in + intake air in = exhaust gas
out + intake air out + heat rejected from the turbo casing.  Shaft work is
not considered, since it is neither added to, nor rejected by, the "closed
system."

We can't even _think_ of evaluating the process w/o definitive consideration
of _all_ components of the equation.  Let me know the results. okay?  I'm as
interested as anyone!

 - Doug

P.S. - Any info on exhaust gas temperature into and out of the turbo?

----- Original Message -----
From: Smith, Kirby A <kirby.a.smith@lmco.com>
To: <quk@isham-research.freeserve.co.uk>
Cc: <quattro@audifans.com>
Sent: Wednesday, October 06, 1999 10:50 AM
Subject: RE: re Re: Ceramic coating EM's - II


> I get your point, although kinetic enegy is proportional to velocity
> squared.  The actual physical effect is molecular momentum transfer to the
> blades, which are shaped in a manner to exert work on the shaft while
> redirecting the molecules out of the way of the "unused" molecules.  Gas
> kinetic energy in the form of heat could conceivable contribute.  If the
gas
> temperature before the turbine was the same as after the turbine (for the
> same size pipe) then all energy is taken from gas flow.  If otherwise, I
> would argue that some came from heat.  I will defer further comments until
I
> have time to check out my sources to see if my head is wedged in this
case.
>
> kirby
>
> > -----Original Message-----
> > From: quk@isham-research.demon.co.uk
[SMTP:quk@isham-research.demon.co.uk]
> > Sent: Wednesday, October 06, 1999 1:39 PM
> > To: kirby.a.smith@lmco.com
> > Cc: quattro@audifans.com
> > Subject: Re: re  Re: Ceramic coating EM's - II
> >
> > In message
> > <A955A4BCA8F8D011AE1C0000F804A88A0413C6C5@emss05m02.sanders.lmco.com>
> > "Smith, Kirby A" writes:
> >
> > >> No, it converts kinetic energy into heat.  The fact that exhaust gas
> > >> is hot has nothing to do with it - it would be just as happy with
> > >> cold gas input.
> > >
> > > Hmmm Phil, I'm not sure I would embrace this perspective.  Your first
> > > sentence is literally true over the entire system.  The exhaust
kinetic
> > > energy is used to perform work on the exhaust turbine (which is
attached
> > to
> > > the intake side compressor of course, pressurizing the intake manifold
> > and
> > > in the process generating heat).  If the gas kinetic energy is
partially
> > > used, the temperature of the gas will fall for that reason, as well as
> > due
> > > to the drop from any pressure fall across the turbine.
> >
> > Kinetic energy is mass times velocity.  Mass cannot be altered outside
> > of nuclear reactors - only velocity is available.  The blades are spun
> > effectively by pressure - a differential between the manifold and the
> > downpipe.  Heat has absolutely nothing to do with turbine operation -
> > it's just a way of expanding the volume of an available gas to make it
> > do physical work.  Once combustion is complete, the temperature of the
> > gas starts to fall - to the point where you can put your hand in the
> > tailpipe stream.
> >
> > Heat is a form of potential energy, but there's no way of using it in
> > a turbine.  In such a device, it's merely a nuisance.
> >
> > > I do not believe your second sentence agrees with my understanding of
> > turbos
> > > from books I have read.  I believe the shape of turbines, whether jet
> > engine
> > > or in turbosuperchargers, is designed to use both flow and
temperature.
> > > This may all be semantic, as heat is kinetic energy in a gas.  The
> > kinetic
> > > energy is both random and directional, and both may be used in a heat
> > > engine.
> >
> > What physical effect exploits the temperature of the gas?  No water is
> > boiled to make steam.  The effects are purely physical - the exertion
> > of pressure against the blades.
> >
> > --
> >  Phil Payne
> >  UK Audi quattro Owners Club
> >  Phone: 07785 302803   Fax: 0870 0883933
>