Originally Posted by
NutLoose
Err why are you having a pop at me? and quoting someone else? Perhaps one needs glasses. I wasn't the one asking the question. I would point out though FADEC is on everything these days, not just turbines.
And for your info as you appear to be having an unwarranted pop at me, I was an A Tech P in the RAF and post RAF have worked on Learjets, Beechjets, Citations, Gulfstreams, Falcons and turboprops galore.
..
Well said.
I don't understand why the subject of FADEC is being referred to in this instance.
But to clarify.
A GT engine may feature either Inlet Guide Vanes at the front of a compressor or Variable Guide Vanes or Bleed/Blow Off Valve at the rear of the compressor.
Both of these features would be controlled by the FADEC.
However, these are specifically to act as airflow aerodynamic devices to either raise the surge line or reduce the compressor running line.
But they would not be able to cope with compressor mechanical damage resulting in a surge.
On a typical modern GT, with a pressure ratio of over 25/1, a surge would happen incredibly quickly.
Certainly significantly faster than the normal FADEC data refresh rate of around 5 to 10Hz. And there is then the matter of the IGV/VGV/BV response time.
This would be nothing like fast enough to get anywhere near able to react to a compressor mechanical damage caused surge. And should the damage become serious enough, the surge would lock in meaning that the engine would have be either throttled back or more likely shut down.