Consider an aircraft powered by a turbojet engine that has a pressure ratio of 12. The aircraft is stationary on the ground, held in position by its brakes. The ambient air is at 27 deg.C and 95 kPa and enters the engine at a rate of 10 kg/s. The jet fuel has a heating value of 42,700 kJ/kg, and it is burned completely at a rate of 0.2 kg/s. Neglecting the effect of the diffuser and disregarding the slight increase in mass at the engine exit as well as the inefficiencies of engine components, determine the force that must be applied on the brakes to hold the plane stationary.

The container truck engine operated on the diesel cycle with a compression ratio of 12. Assume the mass of air in the engine is conserved. At the start of the compression process, the air is at 1 atm and 30 oC. 400 kJ/kg of heat is removed from the air during the constant-volume heat rejection process. The ratio of v3/v4 is 0.2. Through the diesel cycle, 20% of the work done by the air is used to operate the vehicle's refrigeration and heat pump system. One diesel cycle took 0.7s to complete. The heat rejection from the refrigeration and heat pump system is 800 kJ. The refrigeration system uses R-134a as the working fluid and operates between 100 kPa and 1200 kPa pressure limits. cp = 1.005 kJ/kg/K, cv = 0.7177 kJ/kg/K, R = 8.314J/mol/K, Molecular mass of air= 29g/mol.   a) Calculate the temperature at the start of the heat rejection process. b) Calculate the temperature at the end of the heat addition process. c) Calculate the temperature at the start of the heat addition process. d)…

What are the effects of varying the compression ratio on the thermal efficiency and power output of an internal combustion engine?

16-16M Consider an air-standard Otto cycle that has a compression ratio of 8.3 and a heat addition of 1456 kJ/kg of air. If the pressure and temperature at the beginning of the compression process are 0.95 bar and 7°C, determine (a) the maximum pressure and temperature for the cycle, (b) the thermal efficiency, and (c) the mean effective pressure, on the basis of Table A-SM. 16 11 nir stand