An internal combustion engine, with compression ratio of 12.5: 1, operates on the dual combustion cycle. 70 % of its total heat supply is taken in at constant volume and 30% at constant pressure. expansion and compression are adiabatic and heat is rejected at constant volume. the pressure limits are 100 kpa and 4600 kpa. ambient temperature is 18º c. r=0,288 kj/kg. k and cv=0,712 kj/kg. k calculate the ideal thermal efficiency of the cycle.