Use this cycle approximation to analyze the following problem: Inlet conditions: Compression ratio: Heat added during combustion:

Diesel engines can be approximated by a dual cycle. In dual cycle, a fraction of the fuel is burnt at constant volume and the remaining fuel is burnt at constant pressure. Use this cycle approximation to analyze the following problem: Inlet conditions: Compression ratio: Heat added during combustion: Fuel-­‐to-­‐air ratio: Υ = Cp/Cv P1 = 1 bar, T1=289K 15:1 43 MJ/kg of fuel 0.045 1.35 Half of the fuel is burnt at constant volume, then half at constant pressure. Draw a P-­‐V diagram and compute the thermal efficiency of the cycle