Question

2. The following information is known for a turbocharged 4-stroke Diesel engine, when running at a certain operating point onboard a vessel: (Geometric) compression ratio: Volumetric ratio: Combustion efficiency Heat input efficiency: Mechanical efficiency Entrapped air efficiency: Intake manifold pressure: Intake manifold temperature: v2 / v, = 20 comb = 98% = 75% m = 90% trap = 100% 3.5 bar (abs) 50°C In the above (see also the figure given at the bottom of the back page). VI: Volume of the cylinder above at start of compression V2: Volume of the cylinder above the piston at Top-Dead-Center (start of combustion) Vs: Volume of the cylinder above the piston at the end of combustion Use air-standard analysis. Consider air as ideal gas with constant R 287 J/(kg K) and ratio of specific heats γ = 1.4. The diesel fuel's lower heating value is 43 kJ/g. (a) Sketch the cycle on a p-v (pressure vs. specific volume) chart. Clearly show the numerical values of the coordinates of all corner points of the cycle. Also, calculate A/F of the engine at this operating point. 5 pts (b) Using the p-v diagram from (a) calculate IMEP, BMEP, SFOC and overall engine efficiency 5 pts.

Answer 1

Solution (Rar) 1.4 20蚩2.sr Pu (a)y valume at Poit V2

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