Burner

[krazycolin]

Anybody here know the correct sequence of events for burner petals? what i'm looking for is the correct way that the petals would open and close from engine idle all the way to full burner.

i know some of you are actual mechanics and the like, so if you could help me out, that'd be great....

thanks,

KC

[Galgot]

Hi colin,
I don't know much about this, it seems at idle the petals are open, then the more throttle, the more it closes. That's for Military Power (dry thrust). Then with Post-combustion it goes full open.
There must be variants of course, like i think i read somewhere that there are some no-pilotable post-combustion ( working just off or on ) and pilotable one's. on these last maybe the petals position varies with the power...
But then again , I'm no expert, noticed this from various films...

[krazycolin]

what i have is actually different than that. it seems that it's closed at low throttle/idle and opens up as it power increases... then.. just as you pass the stops for military power into afterburner, the petals close up and then open up fully.... this is to prevent flameout.

(this is directly from David Donald) (if you don't know who he is... well... then... what can i say...)

[Galgot]

Well... don't know either...:p
Checked on YouTube and found this :
http://www.youtube.com/watch?v=YWaZSoC_Ohc
http://www.youtube.com/watch?v=Pn9HYrqQ6O8&mode=related&search=
See how when power is added the nozzle closes, then when it passes to PC it goes open...