<< 4.  How can Mazda exhausts run 'hotter'? than other IC engines??  In
'Thermo
 > of IC Engine', we were taught that burning temperatures of various fuels
 > were characteristic of the properties of the fuel and the air:fuel mixtures
 > being burned........not what kind of vessel within which they were being
 > burned??  It is apparent that the BSFC of Mazda...at least at high power
 > outputs is higher than most other C/S/Piston IC engines and more of the
fuel
 > energy taken in is rejected out the exhaust.  My question....how does it
get
 > 'hotter' ie..higher temperatures, than any other spark IC engine at the
same
 > air:fuel mixture ratio >>

The *peak* temperature of the gas due to burning is largely related to
mixture among other things but we typically measure *exhaust* temperature.
Exhaust temperature is a strong function of expansion ratio after burning.
The rotary has a higher percentage of fuel mixture burned later in the
expansion cycle.  The late burned mixture is not expanded as much and is
therefore hotter and makes the overall measured temperature higher.

Jeff Spitzer

 
The AirCraft Rotary Engine NewsLetter.              Powered by Linux.

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