Can I set any JSBsim FDM property with a FDM function ?

[benih]

Did not work. There is no such property to set in run time, only in the engine definiton as <value>.
I need this at runtime.

[S&J]

What can I say....

You can lead a horse to water....

[benih]

That was not helpful.

[S&J]

Ok how about this.

I can't look for you, only you can do that.

I've been adjusting it for years

[TheEagle]

You need to change /fdm/jsbsim/propulsion/engine/bsfc-lbshp_hr. Works for me through the property browser. But it's counterintuitive - the lower you set it, the more power you get, so if you want less power, you need to increase it. Also you need to take care that it never becomes 0 - when I set it to 0, the FDM crashed immediately.

[S&J]

thank you Eagle...

It's the 6th property down from the top.

[benih]

Oh thanks!
That one i already checked, but had the side effect of adjusting the fuel flow too.
I already have this with my current solution (adding friction to slow the engine).

[S&J]

That's because what you've got there is a bandaide on top of a bandaide on top of a bandaide written in either XML or Nasal.

Basically you've got a completely porked piston engine.

Adjusting bsfc does NOT effect the fuel flow

Probably done by someone who never designed a jet engine, right Thorsten ?

[benih]

Are you referring to me or eagle?
I talk about the c182s which is piston driven.

[S&J]

You

[benih]

You

Ok.

I reinvestigated and i think i had a bogus number in my function. I reimplemented it from scratch, and now i can adjust the power (and with that RPM) with an oscillator for rough engine running. And fuel flow does just oscillate minimally - the cause of this is clearly the implementation of the governor, because fuel flow here is also depending on the RPM setting (and RPM is oscillating in this scenario like i said).
I think i probably need to introduce some correction value here, to smooth this out. But first i need to tune the numbers.

[TheEagle]

Great that it is working now, as at some time I will need a similar code on my Cessna 210 !

[S&J]

The issue I have with plug fouling is the time it takes to occur and be resolved. Plus determining the power loss.

[benih]

That is true S&J, but for the magnitude of the effect there is footage online.
The time and conditions for resolving are well known, too.
What I don’t yet have found is the time it takes to foul a plug given the right conditions. I tried to encode the vague reports from real aviation forums into something usable and decided for about 10 minutes (give or take).

If you have something valuable to add in those redirects, you are more than welcome to post it here: viewtopic.php?f=34&t=39770

[benih]

(Removed duplicate thread hint)