I'm trying to estimate the temperature of combustion in an Otto Cycle engine, using a formula based on the First Law:(adsbygoogle = window.adsbygoogle || []).push({});

T4 = T3 + fQ /cv

Where T4 is the combustion temperature, T3 is the air temperature after compression, f is the fuel/air ratio, Q is the heat energy of the fuel, and cv is the specific heat at constant volume.

Assuming T3 is 750 degrees Kelvin, the fuel is gasoline which has a heat content of 43,500 kj/kg, the fuel air ratio is 0.07 (close to stoichiometric), and cv at this temperature is 0.8 kj-kg/K, I get a very high number: 4556 K.

I think the temperature should be much lower. Is there another approach to this problem?

Regards,

Gordon.

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# Homework Help: Thermodynamics Otto Cycle engine

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