An air-standard Otto cycle starts compression at 200 kPa and 26.85°C. Constant-volume heat addition is 1.02 MJ/kg and efficiency is 50%. Assume ideal gas with constant γ = 4/3 and c_v = 0.85 kJ/(kg·K). Find maximum cycle pressure (one decimal MPa).
Otto efficiency gives $1-r^{1-\gamma}=0.5$, so $r^{1/3}=2$ and r = 8. Initial temperature is 300 K; isentropic compression gives T₂ = 600 K and $p_2=p_1r^\gamma=0.2(16)=3.2$ MPa. Heating raises temperature by 1020/0.85 = 1200 K to T₃ = 1800 K. At fixed volume, $p_3=p_2T_3/T_2=\mathbf{9.6}$ MPa.
More Thermal and Fluids Engineering questions
GATE 2023 PI Q15– Two infinite plane parallel black surfaces exchange thermal radiation. A black radiation…
GATE 2023 PI Q31– A wooden cube of side 0.1 m and specific gravity 0.75 is held submerged by a massless…
GATE 2023 PI Q32– Steam steadily enters a turbine at h₁ = 3200 kJ/kg and exits wet at 0.1 bar. Heat loss is…
GATE 2023 PI Q60– Water flows in a 0.02 m diameter pipe at Reynolds number 1000. The pipe is heated…
GATE 2023 PI Q61– In an ideal air-standard Brayton cycle, compressor inlet is 100 kPa and 300 K. Thermal…
GATE 2022 PI Q27– Water of kinematic viscosity 1 × 10⁻⁶ m²/s flows through an 8 mm horizontal circular pipe.…