Stuart,
here are the annouced changes to the engine code:
- autostart and autoshutdown sequences to work with ECP switches (if someone is wondering: press middle mousebutton on engine main sw. to manually switch from IDLE to OFF position)
- OEI training mode (press "Training" button on ECP)
- Modelled the engine n1/n2 dynamics and fuel system, more complex engine model for spoolup and under different flight conditions (see details below)
- all three tanks (2 supply tanks!) and fuel pumps according to manual (tank levels are also displayed on VMD)
- modelled target NR according to manual (see comments below)
- added FLOATS ARMED message to masterlist
download link (contains just changed files)
Comments on changes in engine code
In general the dynamics of n1/n2 and consequently NR during flight were not well reproduced by the bk117.nas Nasal code as all were kept at 100% at all times.
I found these Youtube videos
https://youtu.be/7fTeLxnIG_s ,
https://youtu.be/d-1z-2H6_iE where n1,n2 and trq dynamics on a EC145 in various flight conditions can be observed.
- the idle n2 datum should be around 78%, not 63% as it has been.
- n1 in flight should be something around 88% and should increase with power demand (I used collective position as a first approximation -> reused the out-commented "droop compensator").
- NR datum ("target" in Yasim notation) should not be constant 100%, but modulate between 96%..106% depending on airspeed and pressure altitude, according to the aircraft manuals I found on the internet.
- Also, NR is expected to "droop" a bit during fast transient power demand, especially in OEI training mode. The old Nasal code supplied max. power to the Yasim FDM at any time, keeping NR rock-steady at 100%.
I have adapted the engine code in bk117.nas, to derive the power made available to Yasim (/controls/rotors/maxreltorque) from n1 and use the Yasim calculated rotor speed in turn as feedback and sync's the engines n2 with it, depending on the engines states.
It is certainly NOT a full fledged engine model but in my trials I found it is able to reproduce typical engine parameters under certain flight conditions and during engine spoolup quite well.
litzi