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

[Black-Talon]

I've learned a few more things about using FAR with Firespitter Wings/Controls in case it's of interest to anyone trying to use both. I have a separate installation for FAR which I enjoy using to make/fly planes. I have Firespitter installed in both my non-FAR version of KSP, and the FAR-enable version. I do enjoy Firespitter in both!

Previously I noted that I was attempting to load and fly Firespitter's (Stock) K-17 in my FAR-enabled version of KSP and I observed a few hiccups that made it impossible to do:

• Controls don't update graphically unless they are locked and then unlocked prior to flight
  
• Even once the control surfaces are updating graphically they don't seem to apply much control to the craft
  
• Take off results in a uncontrolled loop and unintentional rough 'landing' ;-)
  
• For someone familiar with FAR you would notice that the control surfaces aren't configurable in the VAB
  
  These four issues can be resolved by eliminating the FSwingletRangeAdjustment Module from the Firespitter wings and changing the FAR Module from a wing to a control surface.

  
  

Previously I floated some questions about things I didn't understand:

1. It seems a FARControllableSurface is more accurate for the wings with control surfaces? Note that there is some concern noted in both the FAR and Firespitter threads that wings with integrated control surfaces are not yet supported in FAR...but I've found that without at least some tweaks, Firespitter wings are unusable in FAR, but work enjoyably once modified.
   
   This is all confirmed. In order for the Firespitter wings to be used as control surfaces with FAR installed they must be changed to be FAR Control Surfaces. This doesn't model them correctly, it treats the entire wing as a control surface instead of just the actual surface. That said, it does work which is better than not working. The root cause here is that FAR doesn't support this wing type.

   
   

2. The default drag and lift configuration is zeroed out on stock parts...should the same should be true for Firespitter wing/control parts?
   
   The suggestion is that no, there is no need for them to be zeroed out. FAR does that behind the scenes on it's own.

   
   

3. Some of the FAR configuration values used on Firespitter wings aren't documented in the FAR Readme.txt, perhaps they shouldn't be there? Others need to be there instead?
   
   These are older values and don't cause any harm but neither are they needed.

   
   

4. In FAR, when a AoA Sweep analysis is done, only CL is graphed... does the lack of CD and others indicate incorrectly configured parts?
   
   This is caused by the InfoDrive part that is installed on the K-17. A part I really enjoy! While I have no idea why, it seems that a part without a "rescaleFactor" defined in the config will destroy FAR's drag model. By setting "rescaleFactor = 1" for the Info Drive part, all works perfectly.

   
   

By making these minor adjustments I was able to enjoy a fantastic flight of the (Stock) Firespitter K-17 to the south pole and back. Nice!

Easy way to get Firespitter wings working with FAR so that the stock planes can be flown: use this Additional ModuleManager Config to make the modifications noted above. It is simpler than my previous ModuleManager Config and I'm just happy that it lets me enjoy the Stock Planes in my FAR-enabled KSP Installation. The config won't overwrite any parts and can be undone easily at any time by removing the config. Note that it only changes anything if FAR is installed (which comes with the required ModuleManager).

-Talon

[MR4Y]

I know what the White Knight + SS1 combo is. I was referring to the fact that you said that your replica takes off at over Mach 1. And looking at the smoke trails and condensation effects in your second picture, it does indeed look like it's moving along at a substantial clip.

How did you get a captive-carry cargo aircraft to Mach 1 in the first place, much less take off with it?

The White Knight Replica uses 4 TouhouTorpedo Mk4 Jet Engines. I tried with two, but the combo wouldn't take off at 150 m/s because of weight. Since mods got out of hand, I'm gonna redo it so it uses less struts.

On another note...

http://www.youtube.com/watch?v=-A-Yuo-bkPE

[Black-Talon]

On another note...

Well done! Impressive! ...and I'm drooling. ;-)

[MR4Y]

Well done! Impressive! ...and I'm drooling. ;-)

Thanks. And thanks to FAR, the variable geometry makes difference, as the jet accelerates faster with the wings sweeped back.

[MR4Y]

Here's SpaceShipOne 2.0:

[MR4Y]

It's either impossible, or I'm doing something wrong with the White Knight. Two engines are not enough, the central part wobbles, the side attachments derail. I don't want to connect struts across both halves, but there's no other option to reduce wobble.

[camlost]

Here's SpaceShipOne 2.0:

At what altitude and speed does the ship separate from the carrier?

[MR4Y]

At what altitude and speed does the ship separate from the carrier?

I'm yet to test this. Here's White Knight 2.0:

[cxg2827]

has anyone ever had issues when the lift would not be centered, even when you have everything symmetric?

[ferram4]

@foamyesque: Keep in mind that the surface area of the pod-heatshield combo will be slightly larger than the pod alone, which will drive the drag coefficient down. It should still behave the same.

@gracae86: That is a known issue and is only a visual bug. The actual CoL is centered, the indicator is simply wrong.

[MR4Y]

Due to the problems with the Subassembly Manager, a SpaceShipOne + White Knight Flight will have to wait.

[foamyesque]

@foamyesque: Keep in mind that the surface area of the pod-heatshield combo will be slightly larger than the pod alone, which will drive the drag coefficient down. It should still behave the same.

I'm afraid it doesn't. Identical pods, except one has a heatshield and one does not, flying identical trajectories courtesy of hyperedit, with size 2 nodes and the most recent version of FAR. Side by side:

[Resender]

My problem atm is that when I get a plane faster then mach 1.2 my frames drop to 1 fps

[StelarCF]

On the steady state performance thingy, could there be a Sweep Altitude button? I'd like to see how my plane would react at different altitudes, especially for testing spaceplanes (for reentry, for really high altitude flight, etc)

[taniwha]

StelarCF: my understanding is those numbers are all independent from air pressure (density, altitude), and thus sweeping altitude won't show you anything. I'm not certain, but I think the basic idea is lift = A * Cl * Q, where Q is pressure (in atmospheres?) times velocity squared (iirc) (given in flight data), and A is the surface area (given in the dynamic analysis area).

If you're not getting enough lift at high altitude, you pretty much have two choices: have bigger wings or go faster. Well, or make a lighter plane.

[ferram4]

@foamyesque: Is the heatshield very heavy or something? It should be working properly unless the origin of the part is messed up, which would cause the heatshield to not make all the drag that it should.

@Resender: Does this problem still occur if you go very high into the atmosphere before reaching Mach >1.2? It could just be the stock atmospheric effects causing your graphics to lag.

@StelarCF & taniwha: Yep, the coefficients are independent of altitude and velocity. Taniwha's equation is almost correct, except for Q, which is:

Q = air_density (kg * m^-3) * velocity² (m² * s^-2)

[taniwha]

Ah, that's why I thought it might be atmospheres: air at STP (20C, 1atm) is pretty close to 1kg/m^-3. Come to think of it, that makes sense because I knew temperature came into it too, but I wasn't sure how.

[Clamps]

Control surfaces don't appear in my control surfaces list. Any ideas?

Also, the CoL indicator is hugely wrong once I put on control surfaces.

This makes my game unplayable with FAR installed.

I just installed the updated Kethane, are there mod conflicts?

Edited July 2, 2013 by Clamps

[Climberfx]

I Made This. Argo BR revision C.

[Black-Talon]

Control surfaces don't appear in my control surfaces list. Any ideas?

Also, the CoL indicator is hugely wrong once I put on control surfaces.

[pic]

This makes my game unplayable with FAR installed.

I just installed the updated Kethane, are there mod conflicts?

This was working prior to Kethane but not after? Hmm... I would guess that your ModuleManager isn't working, where did you put the ModuleManager.dll? Do you have more than 1 copy of ModuleManager in different locations within the GameData folder (RemoteTech installs by default this way - see link below)? Is it possible that the ModuleManager.dll was overwritten with an older version when installing another mod? Older versions had conflicts with B9, but the newest version (comes with FAR) works very well. If you want examples of how ModuleManager should be installed to eliminate conflicts, I go into a fair bit of detail with screenshots showing where things should be installed in this post .

FWIW, I'm using newest Kethane & FAR and have no issues.

[Black-Talon]

I'm interested in knowing more about how drag is determined by FAR. For example, the above example of the heat-shield, I'm really curious to find out what causes that?

Similarly, does the comparison between these two ships (one with what I'd assume would be high drag components added on) seem correct? I'm only asking to better understand how FAR works and what types of things could go wrong so I can avoid them.

This should be high drag?

This should be much less drag?

[foamyesque]

@foamyesque: Is the heatshield very heavy or something? It should be working properly unless the origin of the part is messed up, which would cause the heatshield to not make all the drag that it should.

Heatshield starting mass is just a hair over 1; check the MJ Vessel Stats window for the total craft masses. It had ablated away to a mass differential of ~0.2 by the end of the re-entry. I am quite confident the additional weight doesn't explain the discrepancy in the drag and velocities.

I can't help you on the meshes. That's a question the DRE maker will have to field; I know he reads this thread.

My own suspicion is that since the heatshields are shaped like a (very blunted) nosecone, FAR is treating them like one, but it's just a guess.

[MR4Y]

I'm interested in knowing more about how drag is determined by FAR. For example, the above example of the heat-shield, I'm really curious to find out what causes that?

Similarly, does the comparison between these two ships (one with what I'd assume would be high drag components added on) seem correct? I'm only asking to better understand how FAR works and what types of things could go wrong so I can avoid them.

This should be high drag?

This should be much less drag?

I believe the panels have no drag values, with or without FAR,which also why they can't be used as wings.

[foamyesque]

Also:

For some reason FAR is forgetting all my control surface assignments. Everything responds to all control inputs (even flaps and airbrakes).

Help?

[Clamps]

I reinstalled FAR and it's still not working. New Kethane breaks it. I only have one modulemanager. Whoever said that they had them working together, I don't believe you.

Hey Ferram, how about a non modulemanager version since MM obviously sucks?

My modulemanager.dll is in the gamedata folder where it should be, I'm not using remotetech, I have the latest version, so WTF?

Going back to old kethane versions is obviously not going to happen, yet is the only solution.

That or deleting it, which I just did, and it fixed my FAR! Woohoo!

Edited July 2, 2013 by Clamps