Reference no: EM131039

1. The initial conditions for an air-standard Otto cycle operating with a compression ratio of 8:1 are 95 kPa and 17^o C. At the beginning of the compression stroke, the cylinder volume is 2.20 L ( 1L=0.001 m³)and 3.60 kJ of heat is added during the constant volume heating process. Calculate the pressure and temperature at end of each process of the cycle, and determine the thermal efficiency and mean effective pressure of the cycle.

2. An ideal Rankine cycle uses water as a working fluid, which circulates at a rate of 80 kg/s. The boiler pressure is 6 Mpa, and the condenser pressure is 10 kpa. The water enters the turbine at 600 C and leaves the condenser as a saturated liquid. Assume that the heat is transferred to the working fluid in the boiler from a reservoir at 1400 K and that the fluid in the condenser rejects heat to the surroundings at 25 C. Calculate the following quatities: (a) The power required to operate the pump; (b) The heat-input rate to the water in the boiler; (c) The power developed by the turbine

3. An ideal Brayton cycle uses air as a working fluid. The air enters the compressor at 101 kpa and 37 C. The pressure ratio of the compressor is 12:1, and the temperature of the air as it leaves the turbine is 497 C. The temperature and the pressure of the surroundings are 37 C and 100 kpa, respectively. Use the air-standard assumptions and determine the following quantities: (a) The work per unit mass required to operate the compressor; (b) The work per unit mass produced by the turbine; (c) The heat transfer per unit mass during the combustion process and during the exhaust process; (d) The irreversibility of the cycle on a unit-mass basis, assuming the temperature of the low- and high-temperature reservoirs ar 37 C and 1300 C, respectively; (e) The thermal efficiency of the cycle.