2015年5月13日 · The N2 is the engine core, and the N2 gauge is used mainly during engine start: on initial starter engagement, the N2 starts turning first, and things like adding fuel+ignition and then later disengaging the starter are based on specified N2 speeds. As long as you have N1 rotation before lighting the engine off, N1 isn't all that important ...

2022年6月16日 · All correct answers here, N1 is the large fan at the front and suffers the same effects as turbo lag in a car. N2 does the main compression of the air before it enters the multistage combustion chambers and mixed with fuel. This then drives a series of turbines where one or two actually drives the N2 compressors and one drives the N1 fan.

2006年9月5日 · For reference, the high pressure section (core, N2) of the CF6-80 rotates at around 10,100 rpm at 100% and the fan and low pressure section (N1) rotates at around 3400 rpms at 100%. This is the stuff that makes bearing engineers crazy-especially when you have a three spool engine like the Garrett ATF3

N1 or N2 show the percentage of rpm for the respective shaft. Each engine has a particular number of rpm corresponding to 100% N1 or N2 in order to make numbers easier to understand for pilots between different engines.

2001年4月12日 · N1 can sometimes exceed 100% on take off. Pilots will sometimes use this as a direct indication of power, so for example typically will use 55-60% N1 on approach, although they do not actively watch this to set power while on approach - when u fly the plane u adjust power automatically to suit the flight profile.

2015年5月13日 · N1 and N2 seem to be derived from both. Wikipedia mentions the speed as a percentage paradigm as a human factors consideration, though as of 5/14/2015 there are no references to support this. However, there may be a scientific basis behind this as well, since a change in N is proportional to the resultant change in airflow (i.e. thrust produced):

2016年1月21日 · For the GE90 N1 and N2 speed signals come from speed sensors, each with three outputs. The LP and HP shafts each have a wheel with teeth that cause electromagnetic pulses as they go by the speed sensors. One N1 speed sensor output goes to channel A of the EEC. The other goes to channel B. The third speed sensor output goes to the EDIU, AIMS ...

degraded HPC: 100 rpm N1 inc., 200 rpm N2 inc, 7% in in fuel flow, 150 deg inc in EGT etc... Then, create multiple examples of each fault by add a random amount of noise to each parameter, say < or up to 1% of full scale value (and you can make full scale up as well, let’s say, N1 = 8,500 rpm, N2 = 12,250 rpm, fuel flow = 3.2 lb/s, EGT = 650 ...

2017年4月13日 · N1, N2, and N3—each shaft is given a number, in a single-spool there'll just be a single RPM readout. To run the fan even more efficiently, enter the geared turbofan , where the fan is slowed even further using a reduction gearbox, allowing for an even bigger fan that runs slower—and quieter.

2018年1月17日 · Above graph is from The Jet Engine by Rolls Royce, and shows that the LP spool (N1) starts to turn in the dry cranking (starting) phase, after N2 has been accelerating for a while. The speed with which N1 spools up depends on the engine type, but even the large inertia of a helicopter rotor is slowly starting to be driven around by the starter ...