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

[Beetlecat]

@Ferram4: Thank you -- that's a fair assessment and glad my install is WAD.

[dmitralk]

I use this awesome mod for a long time and now I have a problem whith air breaks. I am actually don't know how to make air brakes and need to fly for a long time with engins off to reduce speed. I know that this information should be some were but I failed to find.

[tetryds]

I use this awesome mod for a long time and now I have a problem whith air breaks. I am actually don't know how to make air brakes and need to fly for a long time with engins off to reduce speed. I know that this information should be some were but I failed to find.

You can use flaps to increase your lift and drag, then use spoilers to decrease the lift and increase drag even more.

It's not hard to find out what they are about.

Also, retroboosters.

[Renegrade]

You can use flaps to increase your lift and drag, then use spoilers to decrease the lift and increase drag even more.

Yeah, some of my dual flap/spoiler designs can go from 0.015 cd to 0.049; they're usually light so they dump speed fairly fast, or maintain speed even in a 20-degree dive. Helps quite a bit.

I just wish the increase/decrease flap/spoiler macros weren't so easy to lose. That stock bug that affects symmetrical placed parts re: action groups not being replicated is quite annoying.

[thorfinn]

@Beetlecat: No, that is correct behavior. This is because control linkages between control surfaces and the appropriate control systems cannot be magically created or destroyed in flight as needed. Once the plane is designed, its control surfaces do X until it's brought back into the hangar for maintenance.

Well, on an Airbus you would just need to change a FCS control law (potentially with a pushbutton) to have any surface do whatever you want, but it's fair

A test plane I used during the low-drag change.

Excuuuuuuuse me...

0.11 lift to drag, 0.5 lift to weight, AND you are flying straight... which means that you have >4.5 thrust to weight?

Edited August 20, 2014 by thorfinn

[spookydonut]

Has modstatistics been removed from just the latest release or from all releases?

[Temeter]

I tried this mod for some days and it's amazing stuff! Weird that people think it's harder, my planes actually tend to fly better with ARM than without.^^'

That said, i had some issues with bigger space-planes. When i level the planes to accelerate to high speeds (1.2k+ m/s at 20 to 30k m), their nose tends to move downwards, and it's hard to stabilize them or ascent. What do i need to consider when constructing for stability during these maneuvers?

Has modstatistics been removed from just the latest release or from all releases?

AFAIK you can just remove gamestats from your gamedata-folder if you don't like it. Not really an issue.

[ethernet]

AFAIK you can just remove gamestats from your gamedata-folder if you don't like it. Not really an issue.

It will be tomorrow when the new mod rules go into effect, as all released versions of ModStatistics violate them (no in-game opt-in for personal info collection, no "forget my info" option available). Any available release of FAR that includes it could be in violation, even if it isn't the latest.

[tetryds]

That said, i had some issues with bigger space-planes. When i level the planes to accelerate to high speeds (1.2k+ m/s at 20 to 30k m), their nose tends to move downwards, and it's hard to stabilize them or ascent. What do i need to consider when constructing for stability during these maneuvers?

Well, it depends on your design.

It's hard to say "this is what you have to do", in a way it will always work.

Normally you would want to increase the angle of attack of the wings, but, as I said, it can be or not a good idea.

Send a pic of your plane and it will be much easier to help.

[Temeter]

Well, it depends on your design.

It's hard to say "this is what you have to do", in a way it will always work.

Normally you would want to increase the angle of attack of the wings, but, as I said, it can be or not a good idea.

Send a pic of your plane and it will be much easier to help.

Thanks, i'll make some pics tomorrow. It's pretty late over here.

It will be tomorrow when the new mod rules go into effect, as all released versions of ModStatistics violate them (no in-game opt-in for personal info collection, no "forget my info" option available). Any available release of FAR that includes it could be in violation, even if it isn't the latest.

I see. Wasn't aware SQUAD already changed the rules.

[Entropius]

edit: Never mind, managed to fix the problem myself.

Edited August 21, 2014 by Entropius
fixed

[Entropius]

I know FAR nerfed the thrust of engines to accommodate other drag changes, but is there a way to omit the nerf to the B9 VTOL Jet engine? That thing really does need it's original thrust, even at sea level, otherwise it's entire purpose is defeated, you know, taking off vertically.

[ferram4]

@spookydonut: It has been removed from all releases that are linked currently. Since I can't delete or remove access to older archived KerbalStuff downloads, I've pulled that link until I can be bothered nuking the mod pages and rebuilding them entirely. On Github, it has been removed from the most recent link, and all older releases that previously included it have been pulled.

@Entropius: You could figure out the module manager syntax necessary to exempt them from the nerf, but based on their sizes and the fact that they're working with vectored thrust, I seriously doubt they should be able to manage 116 kN of thrust per jet.

[Wanderfound]

Thanks, i'll make some pics tomorrow. It's pretty late over here.

Make the pics in the SPH, from top and side, with CoM/CoL/CoT indicators on.

However, most likely suspects:

* Too much drag.

* Insufficient pitch authority.

Drag increases and shifts backwards once you've gone supersonic; this tends to pull the nose down. Conventional control surfaces also lose much of their effectiveness. It tends to be worse on large planes, because they have more drag and lack the agility or TWR to overcome it.

All-moving surfaces (AV-R8's, canards etc.) near the nose may help, as may a general streamlining overhaul. As a last-ditch brute-force measure, a few Vernors under the nose may also come in handy.

[tetryds]

Make the pics in the SPH, from top and side, with CoM/CoL/CoT indicators on.

However, most likely suspects:

* Too much drag.

* Insufficient pitch authority.

Drag increases and shifts backwards once you've gone supersonic; this tends to pull the nose down. Conventional control surfaces also lose much of their effectiveness. It tends to be worse on large planes, because they have more drag and lack the agility or TWR to overcome it.

All-moving surfaces (AV-R8's, canards etc.) near the nose may help, as may a general streamlining overhaul. As a last-ditch brute-force measure, a few Vernors under the nose may also come in handy.

Yeah, those are also solutions, but too much control authority can bring more issues than solve, depending on the design.

Since he is messing with biger spaceplanes increasing the control too much will likely cause them to stall.

If its a delta wing, more control can be the solution, but trimming on the editor can help too.

Let's wait for the pictures.

[Entropius]

@Entropius: You could figure out the module manager syntax necessary to exempt them from the nerf, but based on their sizes and the fact that they're working with vectored thrust, I seriously doubt they should be able to manage 116 kN of thrust per jet.

By this logic the stock jet engines shouldn't be even as powerful as the nerf allows them to be because their engine sizes are unrealistically short. Most real jet engines are several times longer inside the fuselage than the section you can see that's externally visible. I think in KSP there's an implicit assumption that there's more engine hidden away in whatever fuselage or pylon they're attached to. We could assume the same of the B9 VTOLs, that the bulk of the engine is internal somewhere and the visible part is just vectoring the thrust. So if we go with the assumption there's internally hidden engine components (as we do with stock engines), it becomes easier to justify the numbers. The real life Pegasus 11 Mk 107 offers 110 kN of thrust.

Also, there's something to be said for being "too realistic". I think this is one of those cases where too much realism just gets in the way of the game being enjoyable, like a RSS-sized Kerbin would be.

[ferram4]

So, then the total thrust coming out of all the vectoring jets should sum up to 110 kN, not be 110 kN per vectoring jet. With that set up, adding 2 or 4 jets to have the same kind of control a Harrier has, with the current FAR nerf, will result in thrust that's either slightly above or nearly double what the Harrier has to work with. I mean, are you lightening the thing down to below 14 tonnes like the Harrier needs to take off? Honestly, if your goal is to lift a small building off the ground vertically, you don't want jet engines for that. You want rocket engines; TWR is their main virtue.

I've never gotten the "too realistic" argument with respect to changing the numbers that go into a particular function. Frankly, I think RSS-sized Kerbin is awesome, because it acts like you would expect. Besides, the goal here is accuracy in aerodynamic modeling, with only minor concessions to gameplay; I'm already conceding that jet engines should remain super-ultra-crazy-drink-no-fuel efficient, there is no reason to leave them the oddity of having TWRs higher than rocket engines (considering the main advantage of rocket engines is TWR, that's messed up). Hell, the original point of the nerf was to keep the game enjoyable so it wasn't attach-engine-achieve-orbital-velocity-in-atmosphere.

I'm starting to think I should just strip out all the jet engine behavior and tell everyone, "You want jet engines? Run with AJE, welcome to proper jets and aerodynamics. Want magic thrust things that pretend to be jets? Stick to stock."

[tetryds]

I'm starting to think I should just strip out all the jet engine behavior and tell everyone, "You want jet engines? Run with AJE, welcome to proper jets and aerodynamics. Want magic thrust things that pretend to be jets? Stick to stock."

We are fine with them as they are now.

In fact this is the single time I saw someone complaining about the nerf.

[Threadsinger]

Honestly, if your goal is to lift a small building off the ground vertically, you don't want jet engines for that.

Ah, so you've seen my R&D department. Also, CHALLENGE ACCEPTED.

[Threadsinger]

We are fine with them as they are now.

In fact this is the single time I saw someone complaining about the nerf.

Indeed. Criticism or suggestions are ok, but I picked up this mod to make it harder (and more rewarding) to make spaceplanes. Especially with fusion engines. Oh boy, talk about your "high dynamic loads".

I'd understand though if ferram just wants to focus on the aerodynamic aspect, and leave the engineering side of things to others. (Your changes are cool, though!)

Keep up the good work, ferram!

/ever emerge from Alcubierre space in atmo with FAR enabled? VERY. BAD. THINGS.

[Entropius]

So, then the total thrust coming out of all the vectoring jets should sum up to 110 kN, not be 110 kN per vectoring jet. With that set up, adding 2 or 4 jets to have the same kind of control a Harrier has, with the current FAR nerf, will result in thrust that's either slightly above or nearly double what the Harrier has to work with.

I think it all comes down to what assumptions you make regarding hidden internal components. Do the VTOL vectoring engines (1) all connect to a single internal engine or (2) connect to their own individual internal engine. If it's the latter, than the thrust scaling up with the addition of each engine part is justifiable. At a certain point you run into absurd situations where internal components should leave no room for fuel (but then again the same is true of stock engines).

I mean, are you lightening the thing down to below 14 tonnes like the Harrier needs to take off?

It was actually an 18 ton aircraft, but who's to stay I can't assume I've got 2 hidden Pegasus engines in the fuselage?

I've never gotten the "too realistic" argument with respect to changing the numbers that go into a particular function. Frankly, I think RSS-sized Kerbin is awesome, because it acts like you would expect. Besides, the goal here is accuracy in aerodynamic modeling, with only minor concessions to gameplay; I'm already conceding that jet engines should remain super-ultra-crazy-drink-no-fuel efficient, there is no reason to leave them the oddity of having TWRs higher than rocket engines (considering the main advantage of rocket engines is TWR, that's messed up). Hell, the original point of the nerf was to keep the game enjoyable so it wasn't attach-engine-achieve-orbital-velocity-in-atmosphere.

Yeah, I get all that. And it makes sense with most forward-thrusting jet engines, as they continue to fly, just differently. The thrust-nerf is justified in 90% of cases. I'm just pointing that the negative consequences for VTOLs were significantly greater. In the end it may not be worth bending over backwards to avoid breaking VTOLs, but I didn't see any mention of this issue, so I thought it merited at least a mention.

I'm starting to think I should just strip out all the jet engine behavior and tell everyone, "You want jet engines? Run with AJE, welcome to proper jets and aerodynamics. Want magic thrust things that pretend to be jets? Stick to stock."

It's a tough call to balance this, I dunno.

One recommendation I might make is if you keep the nerf, maybe put it in it's own separate config file (with an obvious name like thrustnerf.cfg). Then if people don't like it, they can just delete that entire file safely, rather than looking for specific lines within FerramAerospaceResearch.cfg (and possibly breaking something). I know Interstellar puts its nerfs to engines in separate configs like that (b9aero.cfg and rapier.cfg).

[tetryds]

Entripius, just pick the previous FAR version.

[Master Tao]

I started using FAR to make building planes easier, and the nerf helps by making it possible build small planes with more realistic numbers of engines. It feels appropriate for the aerodynamic model and gameplay, so I may end up nerfing the RAPIERs on closed-cycle, too.

@entropus:

This MM config should unnerf both B9 VTOL Engines:

@PART[B9_Engine_V?1]:AFTER[FerramAerospaceResearch]:NEEDS[!AJE]{
    @MODULE[ModuleEngines*]
    {
        @maxThrust *= 2.0
    }
}

Edited August 21, 2014 by Master Tao
fixed config to not double the nerf...

[NathanKell]

Pretty sure you mean *= 2.0 there. What you posted will cut the thrust in half *again*.

[Entropius]

Thanks Master Tao.

I know enough to delete configs, but not make my own, specifically I never learned the syntax for the first 2 lines. I should note though that the code you gave actually nerfs my engines further (quarter thrust) but I fixed that by tweaking the thrust multiplier from 0.5 to 2.0:

@PART[B9_Engine_V?1]:AFTER[FerramAerospaceResearch]:NEEDS[!AJE]{
    @MODULE[ModuleEngines*]
    {
        @maxThrust *= 2.0
    }
}