X-Mozilla-Keys:                                                                                 
Paul Yaw wrote:

Paul wrote:

Z wrote:

Not to say that I disagree, but I think that is definitely an open question.  There are
two pieces to the overall efficiency equation, first, combustion efficiency, (efficiency
of converting chemical potential energy to heat), second, thermodynamic efficiency
(efficiency of converting heat energy to mechanical work).

There is no question that rotary engines will never equal reciprocating engines in
the realm of combustion efficiency, for the reasons others have already stated.

However, it is important to remember that the thermodynamic efficiency of the rotary
engine cycle is considerably better than that of the piston engine cycle.

Could you please explain this?  I do not understand.

  This was one

of the things which helped spur interest in the rotary engine in the first place.  With
properly timed intake and exhaust (allowing full extraction of the available heat energy
during the expansion phase), the greater thermodynamic efficiency of the conventional
rotary cycle is more than capable of offsetting the lower combustion efficiency.

If you go beyond this and start talking about using the intake air itself to cool
the rotors and rotor housings, the achievable overall efficiency of the rotary
configuration in fact considerably exceeds that which can be realized in a piston
engine, a fact which the Moeller rotary has already demonstrated.

Did Moller build a rotary with a BSFC in the low fours or high threes?

Paul Yaw

 
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