2 components of combustion chamber
Casing (outer shield/support) and flame tube (inside casing, controls and guides flame)
Combustion process
Compressed air enters.
Fuel nozzles spray fuel into airflow.
Ignited by igniter plug.
After combustion, ignition is switched off.
Combustion continues as fuel and air are continually supplied.
2 conditions for safe combustion
Ratio of air/fuel must be correct
Air velocity slow enough to ensure combustion happens inside chamber
Combustion ratio
15:1 ( air to fuel)
Airflow from compressor split into
Primary and secondary
What airflow is used from compresser
Primary (20-30% of airflow)
Types of combustion chamber
Can, can-annular and annular
What is can type
Older GTE with centrifugal compressors,
What is annular
Most used on modern GTE, 1 flame tube
What is can-annular
Set of flame tubes around combustion section
What is transpiration cooling
Secondary airflow enters tube through radial holes in liner. Air flows through gap between liner
