system (Figure 116).
(a) Air Supply. The air supply for compression is drawn from
outside the engine by the action of two compressors. It is cleaned and
directed to the engine air inlet. From the inlet, the air flows through a low
chamber where it mixes with fuel vapor and burns.
automatically supply the correct amount for varying engine operating
(c) Combustion. Electric ignition in the combustion chamber is
used only during the starting cycle. After the start, a continuous flow of air
the fuel or the air is shut off.
(d) Turbines. Exhaust gas leaves the combustion chamber through
discharge nozzles and forces a twostage turbine to turn. The highpressure
turbine drives the highpressure compressor rotor. The lowpressure turbines
drive the lowpressure compressor rotor. After leaving the lowpressure
turbine, the exhaust gas drives a twostage power turbine. The power turbine
supplies the force to turn the engine power output drive shaft.