Air at 22 kPa, 220K and 250 m/s enters a turbojet engine in flight at an altitude of 10,000m. The diffusor slows the air down to a very low speed relative to its inlet. The pressure ratio across the compressor is 12. The turbine inlet temperature is 1240 K, and the pressure at the nozzle exit is 22 kPa. The diffusor and nozzle processes are isentropic, the compressor and turbine have isentropic efficiencies of 85% and 88%, respectively, and there is no pressure drop for flow through the combustor. Using variable specific heats, determine:
A. The velocity at the nozzle exit in m/s.
B. Consider the addition of an afterburner to the turbojet engine that raises the temperature at the inlet of the nozzle to 1100K. Determine the new velocity at the nozzle exit.