Gas Turbine Combustion System Flashcards
The Combustion Chamber mixes Air and Fuel to allow efficient burning (xx% efficient on a modern engine)
98%
Unlike the Piston Engine, combustion doesn’t result in a sharp rise in blank
Pressure
Within the Combustor the following gas states can be found:
– High blank Pressure – fed from the blank
Static - compressor
Blank air cools the exhaust gases ready for the Turbine stage
Dilution air
What does the dilution airflow do?
Cools are to not damage the turbine
What is velocity of air within an engine?
100ms
What is the air velocity reduced to blank ms before the combustion flame.
3ms
What is the air to fuel ratio where nitrogen oxide production is greatest?
15:1
Due to the interaction between the Primary and Secondary airflow 15:1 in the primary zone is rapidly diluted
– It can be considered that the Gas Turbine engine operates between 45/xx:1
45/130:1
The turbo annular has multiple flame tubes with a common blank
Inner/outer casing
Flame tubes are connected together by inter-connectors to assist flame blank
Propagation (jumping flame)
How many igniters in a turbo-annular?
2
What type of combuster is used on mpdern jets?
Annular
Where is the air flow reduced to 3ms?
In the fuel injector
With the advent of FADEC most engines utilise the Air spray injector
– Incorporates a blank and vortex generator to create a toroidal flame in the primary zone
Swirler
