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

[Senshi]

It gets harder to fly crazy contraptions in-atmosphere with FAR compared to stock.

It gets easier to fly sensible contraptions in-atmosphere with FAR compared to stock.

You really have to try it to figure out if it is what you want. Either you'll enjoy the reward that you get if you get your complex craft to still handle nicely or you'll hate that your slightly fat, non-aerodynamic rocket will be torn asunder by asymmetrical lift and aerodynamic pressure.

[the_bT]

I think I figured out my issue. I don't know who's problem this is, probably not FAR though.

This is what is happening (green is shielded, red is not):

If you make your procedural fairing inline (not a cone) from more than 2 pieces, there is an area which is not inside any of the fairing components. I only tested this with the "Interstage fairing adapter" part, might be working correctly for the regular inline fairings... The interstage thing is kinda strange anyways.

My plane uses 6 parts for its fairing, therefore it has an even larger unshielded area in its cargo hold.

Anyway, it's easy to work around so it's probably not that big an issue. Thanks for the assistance.

[taniwha]

the_bT: That is a highly informative screen-shot. I've had shielding problems with regular fairings using two opposing fairing bases too, and that explains why. I guess maybe the fairing base needs to be taken into account when determining the shielded volume.

[MAKC]

@MAKC: FAR's drag is correct, you just need to fly better / design your planes better. I actually suspect drag might be a tiny bit too low.

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This is a real-sized (it looks bigger because the cockpit is comparatively small since Kerbals are much smaller than humans) fictional jet bomber/interceptor without its combat load and very little fuel in the tanks and to my layman eyes and with that TWR it seems like going past M1.0 shouldn't be a huge problem, yet it is.

The speed is maxed out in every picture and as you can see even with altitude it does not go much faster.

I even shielded the cockpit with an interstage fairing instead of clipping a conical tank into it because it would give me the drag from both the whole cockpit and the conical tank.

You are the expert and I believe you when you say that drag is correct, but maybe it scales wrong with size? I don't know. Something is off.

Edit: The intakes produce 0 drag by the way.

Edit2: Vessel View is set to show drag.

Edited June 4, 2014 by MAKC

[NathanKell]

MAKC: Your ballistic coefficient is quite low (about half of what I would expect). First, that's because your aircraft is a bit light for its size (although as you say, this is with no warload and half fuel), but second, it looks like maybe there are some issues with some parts' drag. Try right-clicking your various parts and see what drag they're producing, and post if anything seems weird.

Also, are you using AJE? If so, what engine is that?

[Taverius]

Look like a B9 D-30F7

[NathanKell]

Taverius, yes, obviously the model is. But AJE uses it for about 4-5 different real jet engines. Hence why I asked if AJE; if AJE wasn't involved, then it would presumably be the stock B9 D-30F7.

[MAKC]

Also, are you using AJE? If so, what engine is that?

Yep I am and Taverius is right. It's a D-30F6. Anyway, I did right-click everything on the plane just to make sure but I didn't notice anything excessive in terms of drag.

[ferram4]

@the_bT: Ah, the more-than-2 can't be made to work in the SPH because of issues attaching things in symmetry, which messes up FAR's ability to figure out what is and isn't supposed to be considered in figuring out the bounds of a particular section of payload fairing. I'll see if I can find a good fix, but for now, fewer parts is better.

@MAKC: Showing the coefficients would probably end up with more information. I don't see anything wrong with how your design is performing honestly. Perhaps you need to climb and then dive through Mach 1.2 or so to get on the other side of the drag rise.

[ferram4]

I need the output_log.txt. That section of KSP.log tells me nothing about what went wrong. You can find it in KSP_Data.

[Lanzfeld]

I installed this mod today and this is great.

Is there a way to not have that little button (toolbar maybe) not be on any screen? I know you can "hide" it to the side but I can still see it. I don't notice it on anyone elses screenshots.

[AndreyATGB]

You don't have any other mod that uses toolbar? If not then come on, it's like 50x50 pixels or something, it won't bother you at all.

[Lanzfeld]

I didn't ask if it would bother me, I asked if it can be removed all together.

I don't see it in any other screenshot so I wonder where it is. Even when you hide it off to the side you still see that tab sticking out but not in these screenshots.

[Taverius]

You must be blind then

In all screenshots where the UI is present, toolbar is present.

You hide the UI with F2.

[somnambulist]

Toolbar also has an option to auto-hide if it's docked to a screen edge.

[luckyhendrix]

I have a problem with these winglets that won't get shielded by the fairing

Here is a screen before putting the fairing : http://i.imgur.com/5bwhUzc.png

and after : http://i.imgur.com/z4Pf4g7.png

The griders and other parts switch from isshielded: False to True when putting the fairing , but not the two winglets and two procedural control surface.

I tried other configuration and oversizing the fairing, but those control surface don't switch to shielded :/

[AndreyATGB]

I have a problem with these winglets that won't get shielded by the fairing

Here is a screen before putting the fairing : http://i.imgur.com/5bwhUzc.png

and after : http://i.imgur.com/z4Pf4g7.png

The griders and other parts switch from isshielded: False to True when putting the fairing , but not the two winglets and two procedural control surface.

I tried other configuration and oversizing the fairing, but those control surface don't switch to shielded :/

I posted this a few weeks ago, Ferram is aware of it. Seems wings and control surfaces don't get shielded anymore for some reason, just gonna have to wait for a fix.

[luckyhendrix]

alright thanks, then I'll guess I'll have wait to try out my duna electric plane

[AndreyATGB]

alright thanks, then I'll guess I'll have wait to try out my duna electric plane

It is possible to launch even with unshielded wings, it won't be easy though. I managed to do it even with RSS so I'm sure you can do it in stock. You basically need huge fins on your rocket all the time you spend in the atmosphere and don't even attempt a gravity turn until almost out of the atmosphere, go straight up and hope it won't flip around.

[luckyhendrix]

Yeah I'll try that , or integrate the part into some sort of a space plane build around it

[MrOnak]

Is there information around how FAR changes the atmospheric drag, pressure, density, scale height and ultimately terminal velocity? I've searched this thread and checked the github wiki but couldn't find anything in-depth.

I'm developing a lander-script with kOS which among other things takes terminal velocity into account in order to determine when to start killing velocity. It works just fine but since it is working with the vanilla scale height etc. at the moment it is off by a bit obviously.

Thanks in advance.

[Starwaster]

Is there information around how FAR changes the atmospheric drag, pressure, density, scale height and ultimately terminal velocity? I've searched this thread and checked the github wiki but couldn't find anything in-depth.

I'm developing a lander-script with kOS which among other things takes terminal velocity into account in order to determine when to start killing velocity. It works just fine but since it is working with the vanilla scale height etc. at the moment it is off by a bit obviously.

Thanks in advance.

drag is the standard drag equation. FAR doesn't actually change pressure or scale height, it uses what the game tells it for a given altitude above a given body. Density is determined by a table that Ferram devised derived from real life counterparts to the in-game planets. i.e. Earth for Kerbin, Mars for Duna, Venus for Eve, etc etc.. that table assumes for instance that Duna is largely CO2 just like Mars and calculates density as though Duna had Mars gas composition.

[MrOnak]

Cool that should make the changes rather simple. Is the density chart used by FAR publicised anywhere?

[taniwha]

MrOnak: atmospheric perssure, density, scale height... no changes (that I know of). Terminal velocity is a function of drag and so no direct change there. Drag... very different. You will have to take reference area Cd and Cl into account, and they both vary with vessel orientation.

[KerikBalm]

Ok... FAR is proving to be a challenge... but I really can't tell what is going on.

I can make small basic jet SSTOs, and small turbot jet SSTOs.

Then I try to make a large payload carrying SSTO, and for some reason between mach 1.2 to 1.4, it just pitches up, no matter how close to 0 I try to keep the AoA, no matter mow much fuel I shift forward.

I tried a complete wing redesign (from a forward and aft wing design, with the engines on the forward wing so that it would balance when tanks were empy) to make a large delta wing.... Still, No luck

violent pitch up at mach 1.4

What gives?