A six-cylinder, four-stroke, 3 L compression ignition engine rotating at 2,000 rpm operates on the Diesel cycle with a compression ratio of 18. The compression process is polytropic with a polytropic exponent of 1.3. The expansion process after combustion is isentropic. The air is at 100 kPa and 300 K at the beginning of compression, and the maximum temperature of the air is 1500 K after combustion. Assume that air is the only working fluid and with the properties: specific heat capacity ratio: 1.4, specific heat at constant pressure: 1.01 kJ/(kg K), specific heat at constant volume: 0.718 kJ/(kg K), gas constant: 0.287 kJ/(kg K), molar mass: 28.97 kg/kmol (NOTE: If you can't determine a value for a part of the question, then solve the remaining parts symbolically or with estimated values).
(a) (1 Mark) Determine the temperature at the end of the compression stroke. (ANS: 714 K)
(b) (1 Mark) Determine the cut-off ratio. (ANS: 2.10)
(c) (1 Mark) Determine the temperature at the end of the expansion stroke. (ANS: 635 K)
(d) (2 Marks) Determine the mass of air consumed in one engine cycle. (ANS: 0.00369 kg)
(e) (1 Mark) Determine the pressure at the end of the compression stroke. (ANS: 4284 kPa)
(f) (4 Marks) Determine the net work produced per engine cycle, in kJ. (ANS: 1.67 kJ)