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

["Smith, Kirby A" <kirby.a.smith@lmco.com>]

"Doug Johnson" <ur-quattro@msn.com> wrote:

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?
>>>>>>>>>>>>
The original point of dissention between me and Phil P. revolves around
whether the exhaust turbine extracts heat (random kinetic energy) as well as
the momentum component (directed kinetic energy) parallel with the average
direction of exhaust flow.  (Keep in mind that the design of the scroll is
intended to increase gas velocity as it approches the fins on the turbine.)
I reviewed both MacGinnis and Bell last night, and both refered to
extracting heat.  However, I don't consider that definitive support for my
position, only for my memory, as popular writers have been known to be
sloppy with their terminology.

What I believe is that the scroll increases velocity without significant
temperature rise, and the gas then expands through the turbine, cooling off
in the process.  Work is done and the energy content of the exhaust is less
than before, while mass flow, of necessity, is constant.  I didn't see any
plots of the temperature difference, but I didn't review the entirety of
both books.  My understanding (from a conversation with someone formerly
here at work doing turbo research 20 years ago for a solar energy project)
is that turbine maps are considered highly proprietary, and that is why only
compressor maps appear in these books.  I expect that with a turbine map,
the temperature and pressure changes would be computable.

Kirby A. Smith   New Hampshire USA
1988 90q Titanium gray, 182 kmi
1988 90q Stone gray, 187 kmi 
1995 S6 Pearl effect, 82 kmi