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Old 13th Sep 2006, 12:19
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barit1
 
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Depends on the temperature/pressure of the day. Any N1-managed engine will have a power management curve in which you enter with ambient conditions and look up the proper N1 for that day. (different temp or pressure => different air density!)

The N1 curve will have two separate regimes:

1) In the flat-rated regime, N1 increases with TAT and altitude, to maintain the constant flat-rated thrust (53K in this case). In this regime, rated TO thrust does not change; the changes in air density with temp & pressure are accounted for by adjusting N1.

2) Above the flat-rating break TAT, N1 decreases with TAT to protect the hot section.

PS - don't let "100% N1" confuse you. It's a purely arbitrary number - equivalent to 3500 rpm IIRC. This value means nothing except to the mechanical guys.

Last edited by barit1; 13th Sep 2006 at 12:29.
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