Question

2. Analyze an Audi 3.0-liter TDI V6 Biturbo diesel engine using an air-standard Diesel cycle that addresses the "real" effects of non-isentropic compression/expansion, air-fuel ratio, fuel heating value, incomplete combustion, exhaust residual, and heat loss. The engine is four-stroke, has six cylinders with a compression ratio of 16.0, and develops maximum power at 4250 rpm. Assume the following: the diesel fuel heating value is Quv 42,600 kJ/kg, the air-to-fuel ratio (AF) at maximum power is 25, and the combustion efficiency (79 is 95%. Assume that there is a 3% exhaust residual from the previous cycle and 25% of the heat input during combustion is lost to the coolant, oil, and ambient air. The mechanical efficiency, which accounts for parasitic losses and friction, is 85%. At the beginning of the compression stroke in non-turbocharged mode, assume the conditions in the cylinder are 98 kPa and 305K. Using the variable specific heat method with isentropic compression/expansion, determine: a. maximum temperature (K) of the cycle, b. maximum pressure (kPa) of the cycle, c. net heat input (kj) per cylinder per cycle, d. net work (kJ) per cylinder per cycle, e. mean effective pressure (kPa), f. thermal efficiency(%) g, overall efficiency(%) h. maximum (at 4250 rpm) total power (kW and hp), i. maximum (at 4250 rpm) brake power (kW and hp), j. brake specific fuel consumption (g/kWh), k. volumetric efficiency (%) using STP air density (288.7K, 101.3 kPa),

Answer 1