Could someone clarify what N1 and N2 mean for me? My understanding is that N1 is the fan speed and N2 is the turbine speed, but they seem to be expressed as a percentage. Is it as a percentage of the max RPM? If so, how come it is possible to get over 100% for an N readout in an aircraft?
Also, I thought that the fan and turbine were linked and therefore would run at the same speed - are N1 and N2 measured on different stages, or do I just have an over-simplified view of how the engine works?
Any help would be greatly appreciated.
Cheers, Ginger
(PS, if anyone has any RPM data for a Rolls BR715, i'd love you to share it!)