flameouts
 

Hi,
Would someone mind explaining why turbine engines are prone to flameouts at low power?
Thank you!

I wouldn't say "prone"
 

Well, it's like the engine in your car. It's easier to stall the engine when it's idling, right?

Sort of a question of inertia....and the mass of air being swallowed by the engine. The bigger the mass (higher power) the less likely to suffer a flameout.

Hope that makes sense.

Additionally, at very low power settings gas turbines usually have much less margin between their operating conditions and something going wrong; that's one reason why it takes a LONG time to spool up from idle power - you can't just start chucking extra fuel flow at the engine because it can't take it - whereas at medium power settings you get better accels because the engine can be fed fuel much faster.

The 'power after 8 seconds' cert rule arises from this behaviour, as does the adoption of a flight idle setting higher than 'ground idle' for many engines.

... and the installation of bleed valves, bleed rings, adjustable stator vanes or any other device susceptible to improve the engine's stability or acceleration, most problems happening in the hi pressure area of the last compressor stages.