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

[jrandom]

I'll be more careful with my intakes. (there's two on the sides as well, but none on the bottom)

I've been diving through the help sections trying to understand how to read the Simulation panel. About all I can figure out right now is "red text == badness" or some such thing.

[FlowerChild]

@FlowerChild: Yell at blizzy78 then. GUI design is not my forte. I get the concerns, but I don't know how to make it clearer to be honest.

Well, there's no yelling involved in any of this, and I hope it wasn't taken that way, but understood

[jrandom]

Balancing out my intakes (there's two matching ones underneath) appears to have fixed my pitch-up issue. With the exception of serious roll-twitches, this flies at mach 5 at 32km (RSS/RO) quite well. I see two red entries in the Stability Derivatives, but I don't know what that means in terms of actual flight.

[flightmaster]

Hey guys, I've done a search but couldn't find too much. I'm just curious as to how accurate this mod is? Does it essentially scale down real rocket launch aerodynamics to take into consideration the size of Kerbin?

[NathanKell]

Nope, it's really real for the atmosphere. I think you're looking for Ferram's other mod KIDS, which does that kind of scaling.

Or use RSS for an Earth-size Kerbin (it's slightly broken in .23 but still playable)

[taniwha]

Ferram Fair enough about the control surface panel.

As for the bug tracker, ok, but I do have a bug to report: FAR spews NREs (in FARGlobalControlFlightObject.LateUpdate) for EVAed kerbals.

[ferram4]

That still happens in the most recent version? I thought I fixed that one.

[taniwha]

Actually, I think I'm on 0.12.2. I'll update and check.

[Sandermatt]

I was just wondering, can you make solar planes (ion engines) in FAR, or are these engines to weak to work?

[AbeS]

what do you mean by that? Using them while still in atmo? I'd be surprised to see a vessel with a TWR higher than 1 with ion engines, and solar panels would break so you would need RTGs

[localSol]

Yes it is possible to use ion engines in atmosphere but the mass of wing parts, batteries and RTGs or solar panels makes it very difficult to get off the ground without a boost from a discardable rocket or something. Propulsion from Near Future or Interstellar may make this sort of non rocket propulsion easier. There was a challenge once to get a rover to orbit using only ion engines on minmus, hilariously fun and fast but I couldn't quite do it there even with no atmosphere and lower gravity than duna. Firespitter's Electric Propellers or SMA's Electric Ducted Fan(EDF) work in any gas (non-oxygen) and are much more powerful than ion type engines. Interstellar's nuclear thermal jets don't need oxygen either IIRC but need a nuclear reactor attached to that engine.

[somnambulist]

...and solar panels would break so you would need RTGs

The OX-STAT panels are surprisingly resilient. They're flagged as unbreakable in the part cfg and won't be damaged due to atmospheric effects. Get them going fast enough and they might shear off but you won't have that problem with an ion engined lane.

[SFJackBauer]

To what can I attribute the increased L/D ratio I am seeing in 0.23 compared to 0.22? Is it because of the atmosphere composition changes, or perhaps a bug in pWings 0.6? Does the atmosphere need to be tweaked again in RSS?

0.22, FAR 0.11:

0.23 FAR 0.12.3:

This is at 40º AOA. Drag looks similar, but the lift curve is way different. This craft that I could easily re-enter now keeps skipping off the atmosphere. Should I assume the curve is now more realistic and work my way around it?

[NathanKell]

Did you sweep Mach or AoA?

[ferram4]

@SFJackBauer: There were three changes here that I can think of:

1. The first was that the CoL of wings was changed a little, since it wasn't accounting for sweep effects properly.
   
2. Body lift got reduced a bit; probably not the issue though.
   
3. Removed unrealistic extra stalling at high hypersonic angles of attack; previously wings made too much drag at high angles of attack and high mach numbers.

You'll probably want to dip down deeper into the atmosphere at first and then bleed off speed by rolling the shuttle left and right so you can maintain a high angle of attack while not gaining much altitude. You still have a slightly worse L/D ratio than the space shuttle had. This is much closer to the way things should be.

[SFJackBauer]

Thanks, it must be nº 3 certainly. I remember in 0.22 flying stalled all the way down to Mach 8. I avoided doing the S-turns since it is hard to coordinate bank, yaw and pitch at the same time. I'll try it in 0.23.

(Idea - Perhaps I can set the AOA limiter upper and lower limit at 40 and see if it helps)

Edited December 21, 2013 by SFJackBauer

[ferram4]

Use the trim controls to keep a high angle of attack. Even if you use SAS to hold orientation, that will at least help it maintain the same angle of attack when you go to change the roll angle.

[Velorium117]

I'm having an issue just loading up my game. Everything loads fine until it gets to the stock Squad Aero parts (wings and stuff).

This is the link to my crash log: https://dl.dropboxusercontent.com/u/51079552/KSP.log

I know this isn't much of an explanation but there isn't much to explain . The crash log says the issue right at the end. Any ideas?

[ferram4]

Well, it looks like you're running KSP 0.22, and FAR 0.12+ isn't backwards compatible. You'll have to grab the old FAR v0.11 through the mediafire link in the OP if you want to stick with FAR 0.22.

That said, the KSP.log is garbage, since it doesn't include a stack trace. You need to post the output_log.txt for it to be useful to any modders.

[Velorium117]

Ohh ok. Yah I'm trying to run the Real Solar System mod and it linked me to Ferram as a required mod, I didn't realize I needed the older version, thank you. And this output log, where do I find it so I know for the future?

[ferram4]

It's in KSP_Data. The advantage of it over KSP.log is that it includes info that will point directly to where everything is breaking, which provides a good starting point.

[Camacha]

The aircraft I am currently working on is consistently rolling/yawing a bit to the left when commanded to pitch down, and rolling/yawing a bit to the right when commanded to pitch up. I removed all the loose bits on the outside of the craft to ensure those are not the cause. Could this be caused by that different flexing of stressed joints-fenomena? It is not a huge bother, I am just trying to find out whether it is something I can fix or not.

I must say that a couple of nights spent tweaking this version of the aircraft greatly increased my understanding of what influence the position of the CoM has on stability, how the CoM and CoL interact - resulting in different pitch rates - and how stability is affected by that pitch rate (or any deviation from prograde for that matter).

I now understand that I got a bit lucky with the previous version (tragically lost in a hangar/harddrive fire), and also that one of its undesired properties was directly linked to what I did like about it. Fixing just the first was less trivial than I thought and is really about striking a balance. It is interesting to see that incremental improvements made to better the handling of the craft slowly led to a design that also looks very much like the previous model - albeit with some minor changes to fix the problems that it had. Form very much follows function.

I am really enjoying the mod!

[jrandom]

Camacha, if you get RCS Build Aid you can display your Dry Center of Mass, meaning that if you keep the dComM right on your CoM you can build planes that are stable regardless of how much fuel is left. That little tool taught me a lot on how to place fuel in an aircraft. (Especially since we can't exactly stuff it into wings like a real aircraft, although I'm pretty sure a combination of Modular Fuel System and come custom .cfgs for ModuleManager could correct that.)

[SFJackBauer]

Hi, me again

There is some weirdness with flaps on my end. First, the actions "Increase Flap Deflection" and "Decrease Flap Deflection", when assigned to action groups, change the flaps only one step in either direction and then stop working.

Also when in flight, and right-clicking and selecting "Deflect more" or "Deflect less" the surfaces visually do not go through all steps, only the first two.

While typing went back and checked that it is the same bug you said you fixed for the next version, about the brakes max deflection being ignored. Same with flaps.

Finally, the flaps to start already deployed when going to the runway, although at step 2. Is it for the pilot to not forget it for take-off?

[NathanKell]

Be careful though, since RCS Build Aid isn't updated for .23 and tries to call a missing EditorLogic method (works for a while, spewing to log, but eventually dies).