Hi,
the purpose of the initial "standing up" is clear.
The virtual pilot's target is not an EPR value but circa 50% of the mechanical thrust lever range, i.e. 25° TLA (thrust lever angle). There is no special intention behind the fact that 25° results in 1.25 EPR. The result is different on all three engine models.
If you can tell me more about the PW's ratio of TLA versus EPR I might be able to fine-tune the translation in the EEC for the fuel valve control.
The PW engine's EPR model is the most complex of all three engine types as it uses the "core EPR" method to indicate EPR values -- unlike the RR model which uses the "integrated EPR" method. The PW EPR varies very much with the Mach number. As you know, in an idle descent it can go as low as 0.75 EPR, where the RR wouldn't indicate less than 0.98 EPR.
It could also be that I should fine-tune the TLA/EEC ratio on
all three engine models towards a more curved, less linear translation? Comments are welcome.
Should we have more fine-control in the upper thrust range or more in the lower thrust range?
For example, I could put the PW's 1.25 EPR target along a curved, non-linear translation on, say, 35° instead of 25°. That would give more fine-control for lower thrust settings (0°-35°), and less fine-control for settings above 1.25 EPR (35°-50°).
Do you see what I mean?
Regards,
|-|ardy
Once 1.10 is set, I expect to see the EGT rise, settle and then decrease slightly ...
This effect is modelled in PSX as well. I just tested it with the Tel Aviv takeoff situation. I set engine #1 thrust to 1.10 EPR, the EGT rises to 350°, and then decreases to 333°.