Question

In an air-standard Otto cycle, the pressure and temperature of air just before the compression stroke are 200 kPa and 26.85 °C, respectively. The combustion process is assumed to be a constant volume process, where 1.02 MJ/kg heat is added. The cycle efficiency is 50%. The adiabatic index $γ$ and specific heat at constant volume $C_v$ can be considered to be constant during the process (corresponding values taken at the mean cycle temperature).
Assuming that the ideal gas law is applicable, $γ = \frac 43$ and $c_v= 0.85\ kJ/kg-K$, the maximum pressure (in MPa) reached during the cycle is _____ . (Rounded off to 1 decimal place)

Answer 1

The answer is: 9.5 or 9.7 (approx.)