In which section of the gas generator are air and fuel mixed together and ignited?

• A. Intake Plenum
• B. Gas Generator High Pressure Section
• C. Combustion Chamber
• D. Power Turbine

Answer: (C)

The combustion chamber is where air from the compressor is mixed with fuel and burned. Fuel is sprayed into the incoming air, forming a fuel-air mixture that is ignited by igniters or a pilot flame. This combustion releases energy, heating the gas to a high temperature and pressure to drive the turbine that follows.

The intake plenum mainly collects and guides air entering the engine, without fuel addition or ignition. The gas generator high‑pressure section delivers the air to the combustor and supports the burners, but the actual mixing and ignition happen in the combustion chamber. The power turbine is downstream of the combustor and uses the hot gases to extract mechanical energy; it does not mix or ignite fuel.