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

[RadarManFromTheMoon]

No, that is not normal.

It seems that the lower tank is hollow.

It's true. The collider PP generates, does not include the "end caps". I'm working on it and hopefully can provide a fix soon.

[ferram4]

@Autochon: To do it right, there are two ways to model the effect of exhaust on the volume displaced by the vehicle:

1. For air-breathing engines, you count the area ducted through the fuselage for the intakes -> engines as hollow and then ignore the exhaust plume itself. That's because most of the mass for that plume starts in the freestream and then returns to it, so it's simple to deal with.
   
2. For rockets, you count the plume as an extension of the vehicle. That's because the exhaust exists only as fuel within the rocket before being dumped out, so it needs to take up additional area.
   

Neither of those is exactly easy to do, so FAR doesn't do either right now. I'm working on the first, might have to come up with something clever for the second.

@B15HOP_xmen: The area rule is wave drag.

[ferram4]

Alright, so FAR v0.15.2, "Ferri" is out. Lotsa bugfixes, and somewhat more accurate voxelization. All of the recent really nasty bugs should be gone.

[Nerd1000]

May I ask how FAR handles flaps? My MiG-23 knockoff has large full span flaps on a high aspect ratio wing, much like the real aircraft, however If I deflect the flaps more than 15 degrees or so they inevitably stall, even when the plane itself is at low AoA. Many real-life planes deflect their flaps to much higher angles relative to the wing. Are these planes flying with their flap surfaces stalled, or am I experiencing some artifact of how FAR handles them?

Also, do you think we could have an option to adjust the upper and lower deflection limits for control surfaces separately? It would allow you to roll using spoilers or use differential deflection of the ailerons to reduce adverse yaw.

[BudgetHedgehog]

Can I just say, naming updates rather than just relying on numbers is a lot easier to deal with. It's way more memorable and can help with support as well - 'I have Fanno installed, is that the latest?, 'No, you need to update to Ferri' - rather than double checking of it's 0.15.1 or 2 or whatever.. Yeah, I like the named updates. Good call.

[CitizenAerospace]

Im guessing the latest version of FAR won't work with 0.9? I play a semi-realistic save (64k system, realfuels, all that good stuff) and none of my mods are updated for 1.0 yet, but I still want the new aerodynamic model on Far : (

[blowfish]

Im guessing the latest version of FAR won't work with 0.9? I play a semi-realistic save (64k system, realfuels, all that good stuff) and none of my mods are updated for 1.0 yet, but I still want the new aerodynamic model on Far : (

You're correct, it will not. There were a substantial number of API changes that took place in 1.0, meaning that some very significant changes had to take place with respect to how plugins like FAR interact with the game. So for now you'll either just have to live with with older versions of FAR (0.14.x) or accept a smaller list of mods (or learn to mod and update them yourself ).

[CitizenAerospace]

You're correct, it will not. There were a substantial number of API changes that took place in 1.0, meaning that some very significant changes had to take place with respect to how plugins like FAR interact with the game. So for now you'll either just have to live with with older versions of FAR (0.14.x) or accept a smaller list of mods (or learn to mod and update them yourself ).

Haha its all good, wasn't expecting it to...

[BigNose]

Alright, so FAR v0.15.2, "Ferri" is out. Lotsa bugfixes, and somewhat more accurate voxelization. All of the recent really nasty bugs should be gone.

Very nice, thank you! And I need to say one thing: The idea to name the releases after mathematicians and people who worked in the field of aerodynamics is just great and really classy.

[Ser]

Alright, so FAR v0.15.2, "Ferri" is out. Lotsa bugfixes, and somewhat more accurate voxelization. All of the recent really nasty bugs should be gone.

I've tested my issue of parts being heated behind a shield and yes, 1.25m part behind a 2.5m shield is ok. Heating took place only behind "hand scaled" 1.62m shield.

But now I have another issue related to the "Ferri" version.

The following vessel gets torn at the red line once the Thumpers flame out at speed about 300 m/s. After that all debris continue to fly together. Seems like there's some ultra short impulse that causes the vessel to break in two. This happens regardless the KerbalJointReinforcement is used or not. Issue appears only with "Ferri".

In case you want to test it yourself here's the .craft file. Only RealChutes are used, all other parts are stock.

Edited May 21, 2015 by Ser

[luckyhendrix]

hello, it seems this version (Ferri) considers the mk2 cargobay as hollow :/.

[ferram4]

@Ser: I cannot reproduce the issue. It has a hell of a lot of wave drag, but SRBs burn out and it continues in one piece no problem.

@luckyhendrix: *sigh* I know what's wrong. Dealing with the idiosyncracies of a messed up game engine are the reason why you don't accept code cleanup PRs from other people. I shouldn't have, but I did, and now I have to go through all the bugs that I fixed with this during development AGAIN.

I guess I'll have to make sure there aren't any other bugs and rush Froude out then...

Edit: Alright, I have it fixed in the dev build. I'll wait on pushing Froude out because NathanKell had some concerns about blunt body drag that I need to look at.

MOAR edit: Just rederived some hypersonic drag equations and I think I see what he was talking about; I made an error in the calculations that I think will make blunt bodies not quite as draggy as they should be. Change is also on the dev build, but I have not tested it yet.

Edited May 21, 2015 by ferram4

[Ser]

@Ser: I cannot reproduce the issue. It has a hell of a lot of wave drag, but SRBs burn out and it continues in one piece no problem..

Hell, seems like there's a nasty little mod that causes it... I think I can guess what it might be: some fix giving physics significance to the decoupler.

[Volt]

I think I may have found another little something while trying to build my first supersonic. The stability numbers are all green, all graphs looking good. But first time I took it off it started slipping to the right as if there was an asymmetry, and it just kept going. Full left rudder didn't help. I checked over to see if I'd missed any symmetry and then I checked the debug voxels:

Images removed to gallery for everyone's sake

Are they supposed to be thicker, and in larger numbers, on one side than the other? Everything from the area ruling strake to the trailing edge of the wing and the trailing strake, too, on the left wing have more voxels than the right. Does that mean something's wrong on my end, or on FAR's, or nothing?

Edit: Mega images, oops.

[ferram4]

How did you manage that? I've never seen that in my tests...

[Volt]

You know what, I have no idea. Of note is that the second fuselage back there is the swivelling VTOL engine from the Mk2 expansion pack (the no-texture one). Could that be something to do with it?

[luckyhendrix]

Also , does FAR modifies the thermal properties in any way ? I find it very hard to reenter a spaceplane, the space plane I posted just above cannot reenter ,even at very shallow angles :/. the dyn. pressure is only of 3kPa, and the deceleration is well bellow 1g, yet every time the craft heats up quickly untill the cockpit part explodes :/

[Volt]

This may be a bug with yesterday's dev build (I should probably update...but I was waiting for 15 3...) or a problem with my install, because I've just discovered the voxels on my Tucano look the same (image 2) and straight and level flight looks like (image 1)

More images

Edit: I may have it. I've just switched to a ship that doesn't use *any* B9 PWings. No weirdness there.

Okay, I can confirm, it's something to do with B9 Procedural Wings. An aircraft with the Swept Wing B on it had normal voxels, and when I switched it out for the default-shape B9 wing, the voxels were thicker on one side. Could be a FAR issue or a PWings one. A lot of people in the B9 Pwing thread are complaining of offset CoL issues and I guess this was my first vessel that really exposed it, so I suppose I'll have to wait/ask crzy for a fix, perhaps.

Edited May 21, 2015 by Volt

[kcs123]

I know that sound silly, but have you tried to grab wing for that bugged craft from oposite side(when you first time attached wing to hull) and attach again.

I was having similar issue with COL offset left or right when I was using procedural wings or B9 Pwings. Someone also mentioned that changing part snap (surface/angle) helped.

I will try to check/reproduce same with my crafts and latest dev build.

EDIT:

Confirmed. B9 Procedural wings are broken on my craft too. Trick that I mentioned by attaching deataching wings only partly works. I loaded craft builded with FAR 15.1 that was worked fine and with latest dev build that i just downloaded have the same bug. Attaching/deataching wing forces new voxelization, it looks much better than from loaded craft, but still one side of wing have more voxel points than other.

I'm using StockBug fixes from Claw, those are also messing with symetry, so it can be cause of that behaviour, although stock wings works just fine.

Craft file is available here if needed. Stock parts and B9PW only.

Edited May 21, 2015 by kcs123

[Volt]

Avoiding double posting by posting on top of this one.

First off Ferram I am truly sorry for repeatedly breaking FAR. Especially when I always seem to be doing it with someone else's mod. I was using EVA construction in KIS to remove and re-add my solar panels to my space station, because apparently the fully exposed boxes are 'stowed' and you cannot deploy things while stowed, when my ship vanished and yet more bloody nullrefs came up:

NullReferenceException: Object reference not set to an instance of an object
  at FerramAerospaceResearch.FARGUI.FARFlightGUI.StabilityAugmentation..ctor (.Vessel vessel) [0x00000] in <filename unknown>:0 

  at FerramAerospaceResearch.FARGUI.FARFlightGUI.FlightGUI.Start () [0x00000] in <filename unknown>:0 

There are also some of these:

NullReferenceException: Object reference not set to an instance of an object
  at FerramAerospaceResearch.FARAeroComponents.FARVesselAero.VesselUpdate (Boolean recalcGeoModules) [0x00000] in <filename unknown>:0 

  at FerramAerospaceResearch.FARAeroComponents.FARVesselAero.FixedUpdate () [0x00000] in <filename unknown>:0 

As it turns out, the station was still there, it just shot my EVA point-of-view about 50m away from the station and then slowly moved back, like my Kerbal's CoM was suddenly 50m away in space. So in the spirit of curiosity, I tried it again. Same thing, except this time the panel vanished into Krakenland. Third time around, it didn't shoot the view, but instead went into an endless loop of the GUI error. As usual I ask: Is this KIS's problem or something with the voxels again? Additionally every new panel I place down, following the NRE, is also 'stowed' and unable to be deployed.

I have no luck. I'm constantly breaking the game. It's rather draining.

Original post:

I know that sound silly, but have you tried to grab wing for that bugged craft from oposite side(when you first time attached wing to hull) and attach again.

I was having similar issue with COL offset left or right when I was using procedural wings or B9 Pwings. Someone also mentioned that changing part snap (surface/angle) helped.

I will try to check/reproduce same with my crafts and latest dev build.

EDIT:

Confirmed. B9 Procedural wings are broken on my craft too. Trick that I mentioned by attaching deataching wings only partly works. I loaded craft builded with FAR 15.1 that was worked fine and with latest dev build that i just downloaded have the same bug. Attaching/deataching wing forces new voxelization, it looks much better than from loaded craft, but still one side of wing have more voxel points than other.

I'm using StockBug fixes from Claw, those are also messing with symetry, so it can be cause of that behaviour, although stock wings works just fine.

Craft file is available here if needed. Stock parts and B9PW only.

Just tried it. No luck, the voxels stay biased to one side. By the way Ferram, these debug voxels are the handiest debugging tool I have ever seen. Props...

Edit reply to kcs123: Ahh, yes, of course. I wish I could remove SBFM and get rid of the bug but it fixes some really frustrating airbrake behaviour. I do remember Claw saying that the Symmetry Fix was still liable to have bugs. I'll go cross-post.

Edited May 21, 2015 by Volt
Avoid Double Post

[Gryphon]

Can I just say, naming updates rather than just relying on numbers is a lot easier to deal with. It's way more memorable and can help with support as well - 'I have Fanno installed, is that the latest?, 'No, you need to update to Ferri' - rather than double checking of it's 0.15.1 or 2 or whatever.. Yeah, I like the named updates. Good call.

Also, it means I end up learning about scientists who contributed to our knowledge of aerodynamics.

I wish I could remove SBFM and get rid of the bug but it fixes some really frustrating airbrake behaviour. I do remember Claw saying that the Symmetry Fix was still liable to have bugs. I'll go cross-post.

Remember, you can just remove the symmetry fix and leave the others active.

[RussianIvan]

is it possible to leave the drain function off axis during the game?

[electroconvulsivo]

Hi there,

i took a look at the last few pages and I saw that there are many bug reports but none like mine. I hope it is not duplicated.

Fresh install with nothing else, just FAR, MM and ModularFlightIntegrator; all extracted from the ziped file in OP.

KSP 1.0.2 in a Debian x64.

The problem is that I cannot build a plane, or whatever, because the blue spherical marker (CoL) doesn't follow the wing part. It just appear, without the arrows, near the CoM marker and doesn't move arround. It happens both, VAB and SPH.

Log File: http://m.uploadedit.com/ba3d/143223130139.txt

Thank you for your time, efford and consideration.

Salud!

[Volt]

Okay, so it wasn't the SymmetryActionFix, because I just disabled it. Crap. Now I have two bugs running.

[Enceos]

@ferram4

I realise you are epic busy. I have absolute gratitude for your mod. etc...

I'm curious if ferram includes shock wave drag in combination with the area rule.

Eg in this video:

I recommend anyone using nuFAR watch this video. It blows my mind how much we don't see with regards to real plane designs.

In this one 20 min video I learned triple the information about planes I ever knew before. Thank you so much for sharing! Now I have a much better understanding of all these FAR graphs. This vid should be in OP.

Edited May 21, 2015 by Enceos