Hi All,

I'm completely stuck

I've been trying to find the temperature of air in an otto cycle before the fuel is ignited. I know

exhaust air is 733^C,

Cp is 1005,

air flow mass rate is 0.00460

fuel mass flow rate is 0.000393.

The cal val for fuel is 46.5 Mj/kg,

and im using the equation Q=m x cv (t3-t2)

but...i just get a ridiculous answer every time.

46.58106 x 0.000393=18 kj/kg

1.225 * 0.00460=0.005635

cv=718

Q=m x cv (t3-t2)=>(Q/(m x Cv))-t2=-t1

(18 x 103 / (718 x 0.005635))-1006=3442k for the lower temperature,

I'm not sure whats going wrong.

If anyone could shed some light that would be great

Many thanks