[1.3.1] Ferram Aerospace Research: v0.15.9.1 "Liepmann" 4/2/18

[camlost]

@camlost: For the control surface itself? Meaning, the wing is at 0 AoA, the control surface deflects to 15 AoA, and it's stalling? If that's the case, it's an issue of the wings not having their colliders set up early enough; ultimately, nothing I can do.

Yes, both ailerons stall at the same time, at 15 degrees. Early enough means?

[ferram4]

Before Start() is called for the FARWingAerodynamicModel. Later than that means that FAR isn't going to get interactions right.

[camlost]

Seems like the mesh is setup in the first round of Update()

[taniwha]

Also, testing at Mach 1 is a terrible idea. Most planes behave terribly at Mach 1 and you never spend much time there. Check above an below it, but right near it is a regime you'll not spend much time in.

Just what is considered "near" Mach 1? I do a lot of flying between Mach 0.8 and Mach 1.05 (the latter only in a high-altitude dive), usually around Mach 0.9. You've seen my plane, it's that little sub-sonic plane in which I do a lot of coffin-cornering (~4000km range once I get up to around 20km).

[kcs123]

Just what is considered "near" Mach 1? I do a lot of flying between Mach 0.8 and Mach 1.05 (the latter only in a high-altitude dive), usually around Mach 0.9. You've seen my plane, it's that little sub-sonic plane in which I do a lot of coffin-cornering (~4000km range once I get up to around 20km).

You should run mach sweep analysis in editor. That should give you answer at what speeds your plane is unstable. Usualy unstable speeds are between 0.8 and 1.4 mach, but it vary slightly on each plane design.

Slight unstability can be tolerated in that transition area between 0.8 and 1.4 mach, you should focus on stability with low speeds up to 0.8 mach and 10km altitude, that should provide most fuel efficient plane and for supersonic speeds you should check 15, 20, 25, 30 km and speeds 2 - 6 mach. Those should be "green".

You may also check links in my signature, hope that this will help you.

[taniwha]

kcs123: That's just it: it's never unstable above ~38m/s EAS (and even then, it just wallows), thus my question. In fact, the only times I have trouble with it (so far) is when one of the ailerons stalls. Nasty down low (obviously), but quickly recoverable with at least 100m or so (over water, anyway).

The plane gets off the ground at around 40m/s and so long as I remember to turn the wing leveler off when I need to turn, behaves nicely doing Mach 0.9 at 20km ASL.

My point was that if Mach 0.85-0.9 is considered close, then it is possible to design a plane that's stable when transonic (at least, with FAR's modeling).

[bukschr]

I'm definitely using the 32 bit build. And I didn't get any yelling... I'm just missing the Editor one. The in flight one is there. I did try the 64 bit version. I can try reinstalling KSP altogether.

That seemed to have fixed it. I guess switching from 64 FAR stayed disabled maybe? Thank you for the help.

[Hodo]

kcs123: That's just it: it's never unstable above ~38m/s EAS (and even then, it just wallows), thus my question. In fact, the only times I have trouble with it (so far) is when one of the ailerons stalls. Nasty down low (obviously), but quickly recoverable with at least 100m or so (over water, anyway).

The plane gets off the ground at around 40m/s and so long as I remember to turn the wing leveler off when I need to turn, behaves nicely doing Mach 0.9 at 20km ASL.

My point was that if Mach 0.85-0.9 is considered close, then it is possible to design a plane that's stable when transonic (at least, with FAR's modeling).

I have an aireal survey aircraft modeled after the Boeing 727. At around 0.9 mach to 1.05 mach it will have some serious flight issues, it gets a bit "wonky" and the controls start to stall out. But from .4-.8mach it is a dream to fly. And below mach .4 down to .3 mach or landing speed it is fine as long as the flaps are set 1 notch.

[LayTzz_swe]

Is there any way of turning the engine altering off? so that engines have their default thrust again???

[DaMichel]

Not really unless you want to edit the config files or make your own ModuleManager patch. Have a look at FerramAerospaceResearch.cfg. There is stuff like

@PART[*]:HAS[@MODULE[ModuleEngines*]:HAS[@PROPELLANT[IntakeAir]]]:BEFORE[FerramAerospaceResearch]:NEEDS[!AJE]
{
	@MODULE[ModuleEngines*]
	{
		@maxThrust *= 0.5
	}
}

in there which does the engine alterations.

@Ferram4: Okay, i deleted my old CustomFAR*.cfg. I guess everything else is updated by git and apart from some minor stuff in config.xml i'm at your master head. But i still have problems with intakes. Now the drag is too large i think. On one craft which has a shock cone intake as nose i get a Cd on the intake of around 0.4. That is two orders of magnitude larger than the next attached part, a fuselage piece and still one order of magnitude more than on the engine. The release version 0.14.6 produces Cd values more in line with the other stuff.

[ferram4]

And you have also replaced the old FerramAerospaceResearch.cfg with the one from the repo?

In any case, that sounds correct; inlets have always had drag areas near that value, but previously their area was based on the inlet area the game used. Now it is based on the actual part size, but the drag coefficient is based on the inlet area. This sounds like expected behavior.

[Suko]

Hello! I've recently installed RSS and I was adjusting the game. I've noticed a FAR debug menu, where I can change the atmospheric composition of the planets, so I was wandering which were the realistic options for these numbers. Is there any chart or something so I can set a real life- alike atmosphere?

[ferram4]

They're already pretty close to real-life numbers. If there are any changes, they would likely be included in the MM configs bundled with RSS.

[Suko]

They're already pretty close to real-life numbers. If there are any changes, they would likely be included in the MM configs bundled with RSS.

Thanks! And great job with your mod, FAR is great for those who seek a greater challenge when playing KSP.

[DaMichel]

And you have also replaced the old FerramAerospaceResearch.cfg with the one from the repo?

Apparently yes.

In any case, that sounds correct; inlets have always had drag areas near that value, but previously their area was based on the inlet area the game used. Now it is based on the actual part size, but the drag coefficient is based on the inlet area. This sounds like expected behavior.

Nevermind. You are right. I just checked the drag in comparison to the Aerodynamic Nose Cone part which has similar shape as the Shock Cone Intake. Cd and drag force are similar.

[blowfish]

Thanks! And great job with your mod, FAR is great for those who seek a greater challenge when playing KSP.

Or just want aerodynamics to make sense

[Threadsinger]

Or just want aerodynamics to make sense

Apologies if this is an obvious question - I did read the FAQ, most of the wiki, and did a decent search of the 752 page thread, but:

Is FAR still changing the characteristics of the stock engines for isp, etc? Just curious if that is still the case (it's cool if it is), I thought I remembered awhile ago that ferram might have wanted to remove that feature. Now that I got my first SSTO into orbit using FAR, Jeb is wondering if that's a feat of engineering and piloting panache, or just a function of super-amazing stock jet engines.

[smjjames]

Apologies if this is an obvious question - I did read the FAQ, most of the wiki, and did a decent search of the 752 page thread, but:

Is FAR still changing the characteristics of the stock engines for isp, etc? Just curious if that is still the case (it's cool if it is), I thought I remembered awhile ago that ferram might have wanted to remove that feature. Now that I got my first SSTO into orbit using FAR, Jeb is wondering if that's a feat of engineering and piloting panache, or just a function of super-amazing stock jet engines.

I'm 99.9% sure that it doesn't mess with the stock engines ISP and stuff. You also have to remember that you'll need less delta V to get out of the atmosphere with FAR than with vanilla. I don't know the exact number, but it's somewhere in the 3k zone, I think.

[tetryds]

I'm 99.9% sure that it doesn't mess with the stock engines ISP and stuff. You also have to remember that you'll need less delta V to get out of the atmosphere with FAR than with vanilla. I don't know the exact number, but it's somewhere in the 3k zone, I think.

3.4km/s last time I checked.

And FAR only nerfs jet engines because drag in stock is so much higher than on FAR that they become overpowered.

It does not touch any ISP values at all.

[camlost]

@ferram4,

How do we make sure that Start() of WingManipulator is called before FARBasicDragModel? The pWing is still problematic even if the mesh is updated with Start().

One potentially better solution is FAR provides a public function to update wing interaction that can be called by other plugins.

Also could FAR provide some in-flight info about wing interactions, to make debugging easier?

[ferram4]

It already provides that. pWings already calls that, it just doesn't call it at the end of everything. It may make more sense to do the scaling in OnLoad, since that must always run before Start.

[camlost]

Already calls that? what is the name of the function?

[HoneyFox]

Already calls that? what is the name of the function?

StartInitialization() I think, judging from PWing's source codes which use reflection to invoke it.

EDIT: Looks like there's another TriggerPartColliderUpdate() that's more likely to affect wing-interaction judgement of FAR.

Edited January 8, 2015 by HoneyFox

[Sandworm]

I've been chasing down a problem with FAR for the last couple days. I just tried it on a bone-stock install (FAR + MM) and the same thing is appearing. Basically, FAR drag isn't functioning because the module isn't being properly added to parts. The full log is below, but here is the issue. Does anyone recognize this problem?

This is a stick mk1pod on the launch pad with no other parts.

[LOG 19:18:10.101] ------------------- initializing flight mode... ------------------
[LOG 19:18:10.104] Loading ship from file: /home/rabbit/KSP_90/Stock_90/KSP_Data/../saves/default/Ships/VAB/Auto-Saved Ship.craft
[WRN 19:18:10.116] [Part]: PartModule FARBasicDragModel at mk1pod, index 6: index exceeds module count as defined in cfg.
Looking for FARBasicDragModel in other indices...
[ERR 19:18:10.116] ...no FARBasicDragModel module found on part definition. Skipping...

[LOG 19:18:10.117] Untitled Space Craft loaded!
[LOG 19:18:11.711] putting ship to ground: 14.66247

https://www.dropbox.com/s/hv4y6bk97q9bzra/KSP.log

Edited January 8, 2015 by Sandworm

[smjjames]

Could that help explain why MechJeb hugely overshoots (or undershoots rather) by kilometers when landing in an atmosphere while using FAR?

Edit: My output log is absolutely covered in those errors.

Edited January 8, 2015 by smjjames