Re: Work output - back to ceramic EM - somewhat long

[quk@isham-research.demon.co.uk (Phil Payne)]

In message <008401bf100c$3a5eb340$473ea8d1@rscnwm.com> "Doug Johnson" writes:

> Isn't the "ideal gas law" applicable only to isentropic processes, where no
> energy is transferred in or out of the system?  Sure, no energy is
> transferred in or out of the "entire" turbocharger system, but you can't
> look only at the turbine or the compressor when using this law (i.e., the
> system perimeter would encompass all four gas pipes leading into and out of
> the turbo).  Also, need to account for energy of the gasses themselves,
> going into and out of the "system").  You will need to account for the loss
> associated with higher exhaust gas discharge temperature as it leave the
> turbo.  Sh*t, this is more complicated that can be done with text; it
> deserves two detailed diagrams to completely understand the changes being
> proposed with ceramic coating.  Where am I in error on this one?

Energy lost to cooling on the outer surface of the turbine housing.  In
a car moving forwards at speed, there's quite an airflow in the engine
bay.  Also energy radiated into the engine compartment (take a look at
night) and lost to the oil and water.  All are probably negligible
compared to the energies carried by the gases.

--
 Phil Payne
 UK Audi quattro Owners Club
 Phone: 07785 302803   Fax: 0870 0883933