*** Quoting Jim Dunmyer from a message to Gerry Calhoun ***
JD> blades. Memories of my college physics courses is a bit dim, but 
JD> there's something about the laws of thermodynmamics floating around. 
JD> Achieving high fuel efficiency requires high temperatures and high 
JD> compression ratios. BothDiesel and gas engines benefit from those 
JD> parameters, and I strongly suspect that turbines do too.
Does Clausius ring a bell?
The transformation of heat to work is always dependent on a temperature drop 
and the transfer of heat to a lower temperature level.
This is his interpretation of the law of conservation of energy. (First law 
of thermodynamics).  Simply stated:  When a quantity of heat energy 
disappears, an equivalent quantity of mechanical, electrical, or chemical 
energy appears.
We still need to address the high temperatures and high gas velocities, as 
well as the small problem of inefficiency at a lower rotational speed.
If I recall correctly, the lower the working pressure, gas velocity, and 
shaft speed...the larger the total surface area of the turbine blades 
required to maintain efficiency.
In view of this, I don't see where a turbine small enough for an automotive 
application could avoid running at high temps and speeds...bringing us back 
to the problems of gear reduction, cooling, and lubrication.
Kevin
--- Telegard v3.02/mL
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