YASim Electric Engine?

[D-ECHO]

Hi!
Being impressed by the enormous development of electric aviation I am currently trying to do some electric aircrafts for FG (eGenius, maybe Silent2Electro), therefor is it possible to (simply ) incorporate electric engines in addition to <piston-engine> and <turbine-engine> into yasim?
Regards
D-ECHO

[erik]

Looking at the code Electric engines are not (yet) implemented for YASim.
JSBSim however does support them.

Erik

[Octal450]

You can simulate it. Yasim doesn't simulate fuel or egt or epr right, so the only useful numbers are really the n1 and n2.

[D-ECHO]

The problem is that when using <piston-engine> for example, the idle rpm is too high (0 for electrical engines) and it consumes fuel (which can be worked around, using a fake ballast, but isn't as beautiful as if it was only consuming electricity

[Octal450]

What about a fake fuel tank that keeps being refilled in the system loop?
You change the IDLE RPM.

[jsb]

I did not get to that part of the yasim code yet but I guess it cannot be too difficult to add a new class for electrical engine to yasim. Should we collect our ideas for this here to create a specification?

[D-ECHO]

I think it's good to collect the specification ideas here, so I'll start
-no idle rpm needed
-very little friction (can be variable when varying how much electric power is taken away from the engine)
-almost only propeller-based RPM transition times
-does not consume fuel
-> possibly <battery> element?
-> fixed mass
-> settable energy per weight ratio

[kaklik]

There seems to be an almost complete implementation of the electric engine to Yasim.

https://sourceforge.net/p/flightgear/codetickets/595/

[enrogue]

According to https://sourceforge.net/p/flightgear/fl ... uests/197/

the work has been merged (on 2020-04-25)

[danielHL]

And here is its documentation:
https://wiki.flightgear.org/YASim#electric-engine

[TheEagle]

fixed mass

Really ? I'm not an electrotechnics specialist, but … to drive the plane forward through the air you need energy. If this energy comes from the battery, it has to get lighter ?

[wlbragg]

I don't think electrolysis has a mass or weight component, it is energy yes, not mass. Same for photosynthesis if that would be the energy source.

[TheEagle]

I read it up - actually you are right. But I was also right - a 100 volt battery loses a few picograms upon dechargement !

[Johan G]

While lead-acid batteries are not really used in aircraft, those who have worked with those, like I for example did when I drove a forklift a lot some summers ago, knows that they always vent hydrogen and oxygen from the electrolysis, and that there should be plenty of ventilation at the charging station. That would account for lost mass.

In fact you should always top those batteries off with more water after disconnecting them from the charger. That would usually take some 5-15 seconds, but once, after returning to morning shift after a week on evening shift, it took 3 minutes. Yikes!