Consider the air-standard Otto cycle described in Problem 9.94, operating with a compression ratio of 8:1. In the constant-volume heat-addition process (state 2–state 3), 1800 kJ/kg of energy is transferred to the air. If the cycle begins with air at ambient conditions of 100 kPa and 15° C (state 1), determine the cycle efficiency. Also determine the heat rejected to the atmosphere.

Problem 9.94

1-2 : Internally reversible, adiabatic compression from the maximum volume V_max to the minimum volume V_min.

2-3 : Constant-volume heat addition to a peak cycle temperature T₃.

3-2 : Internally reversible, adiabatic expansion from V_min to V_max.

4-2 : Constant-volume heat rejection to return to the initial state.

Sketch this cycle using P–V and T–S coordinates, labeling each state point (1, 2, 3, and 4).