Q: Hot combustion gases enter the nozzle of a turbojet engine at 260
Hot combustion gases enter the nozzle of a turbojet engine at 260 kPa, 747°C, and 80 m/s, and they exit at a pressure of 85 kPa. Assuming an isentropic efficiency of 92 percent and treating...
See AnswerQ: The exhaust nozzle of a jet engine expands air at 300 kPa
The exhaust nozzle of a jet engine expands air at 300 kPa and 180°C adiabatically to 100 kPa. Determine the air velocity at the exit when the inlet velocity is low and the nozzle isentropic efficiency...
See AnswerQ: An iron block of unknown mass at 185°F is dropped
An iron block of unknown mass at 185°F is dropped into an insulated tank that contains 0.8 ft3 of water at 70°F. At the same time, a paddle wheel driven by a 200-W motor is activated to stir the water...
See AnswerQ: Refrigerant-134a is expanded adiabatically from 100 psia and 100°
Refrigerant-134a is expanded adiabatically from 100 psia and 100°F to a pressure of 10 psia. Determine the entropy generation for this process, in Btu/lbm·R.
See AnswerQ: The pilot of an airplane reads the altitude 6400 m and the
The pilot of an airplane reads the altitude 6400 m and the absolute pressure 45 kPa when flying over a city. Calculate the local atmospheric pressure in that city in kPa and in mmHg. Take the densitie...
See AnswerQ: A frictionless piston–cylinder device contains saturated liquid water at 40
A frictionless piston–cylinder device contains saturated liquid water at 40-psia pressure. Now 600 Btu of heat is transferred to water from a source at 1000°F, and part of the liquid vaporizes at cons...
See AnswerQ: The entropy of steam will (increase, decrease, remain the
The entropy of steam will (increase, decrease, remain the same) as it flows through an actual adiabatic turbine.
See AnswerQ: Air enters a compressor steadily at the ambient conditions of 100 kPa
Air enters a compressor steadily at the ambient conditions of 100 kPa and 22°C and leaves at 800 kPa. Heat is lost from the compressor in the amount of 120 kJ/kg, and the air experiences an entropy de...
See AnswerQ: Steam enters an adiabatic turbine steadily at 7 MPa, 500°
Steam enters an adiabatic turbine steadily at 7 MPa, 500°C, and 45 m/s and leaves at 100 kPa and 75 m/s. If the power output of the turbine is 5 MW and the isentropic efficiency is 77 perce...
See AnswerQ: In an ice-making plant, water at 0°C
In an ice-making plant, water at 0°C is frozen at atmospheric pressure by evaporating saturated R-134a liquid at –16°C. The refrigerant leaves this evaporator a...
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