Thank you, John. I guess I could be more precise about what I need. I'm looking for ways to calculate things like the correlations between fuel flow, gas generator RPM and gas generator acceleration, the twisting moment generated by a propeller at various RPM/pitch (no IAS, runups only), the twisting moment generated by the power turbine...
Yes, I could go the long route. Calculate my way through the engine with pressures, mass flow, fuel/air ratio etc etc. Done that enough to be sick of it. BTW, that doesn't take long, does it?
But since it has to be realtime and with limited computing resources, I want to cheat as much as I can get away with. I'm basically working on figuring out where to cut corners here.
Do you remember where and when you've seen it done? A lot of corporate work has been spent on this obviously but that doesn't do me much good - I need to find information in the public domain.
Cheers,
/ft