[1.8+] Real Fuels

[AdmiralTigerclaw]

AdmiralTigerclaw: is this easily reproducible? (i.e. does it happen every time?) What engine?

As far as I can tell, all engines I've used, all the time. I've had a general mix of engines between stock, AEIS, and KW in my rockets.

The problem seems fairly solid to any instance of coming off the rails* (dropping out of time warp) with an active (currently-staged) engine. As I said, I'm unsure if this is harmless, or if it's causing problems under the hood. I had a physics engine glitch coincide with it, but that was at a splash down. And I know KJR and water physics don't get along on a GOOD day.

* I noted you must come ALL THE WAY out of time warp. KSP's ramp-up and ramp-down of time warp is annoying. You MUST ramp up and then drop all the way down to 1X warp.

EDIT: Okay, I'll take a look.

EDIT2: The alternates you linked... Got a specific config hiding in them? OR just install the whole RO package? Or remove the Real Fuels package and replace with RO? I need to know for test purposes.

Edited January 1, 2014 by AdmiralTigerclaw

[Zander]

Nathan I am unable to replicate the bug, I think it might have been because i was using one certain saved ship file every time i encountered it. trying with a new one and it doesnt happen. Sorry about that.

Also, I have an idea for Real fuels/realism overhaul. Making the engines take an amount of time to get to full thrust or 0 thrust. For example the F1 took like 2 seconds to get up to full thrust after it was ignited, And when they were cut they took a few seconds to fully lose thrust as the remaining propellants in the combustion chamber was used up. Would that be possible to implement? It would be a function of the size of the combustion chamber I think, Small rocket engines would go from 100% to 0% in like half a second. Larger ones may take 2 or 3 seconds to finish burning up the remaining propellants. Something like that.

[NathanKell]

Thanks, that does narrow it down.

Instead of grabbing the whole package then, grab SFJackBauer's RealEngines pack alone here and copy over only realengines_stats.cfg. That will not rescale anything. (And, obvs, delete your old MFS3.3 engines cfg.)

EDIT: Zander: jets do that, so we should be able to enable it for engines.

[ferram4]

Yo Nathan, got some more info for you on the Modular Tanks freaking out on reverting to launch / loading. It's not dependent on stretchies being involved anywhere, nor do fuel lines seem to affect it.

The tests I tried:

1. Central stretchy with 4 radially attached stretchies, no fuel lines; fine on initial launch, after revert symmetry counterparts have no resource mass, making vehicle unbalanced; nulls thrown at ModularFuelTank.get_tank_mass(), originating at OnStart().
   
2. Same test, but radial stretchies replaced with stock fuel tanks; same results as 1.
   
3. Same vehicle as 2, but radial tanks empty; nulls are still thrown, but vehicle isn't unbalanced on revert.

Somewhat related, I was also able to cause the same teleporting tank weirdness (like with my earlier Delta II) when switching to a vehicle with radially-attached fuel tanks while it is in orbit from another vessel / from the Tracking Station. I don't know what's happening in the code, but I would guess that something that the MFT code needs is being set in the VAB / SPH. When going straight to the flight scene without hitting the editor scene that isn't set properly, causing the bug. But I'm speculating.

Output_log.txt in full.

[AdmiralTigerclaw]

Reporting back on more tests.

A KW griffon engine behaved funky with the cfg was changed. It fired full upon igniting the staging and ignored throttle settings. The guage issue did not show up until the tank ran out of fuel, and then reliably duplicated to 3 again.

When switching to a mainsail, I had no alternative options for the mainsail (which I assume is because 'real engines'), I was able to switch fuels back to stock fuel and oxidizer for the tank fueling it, and it operated fine with no gauge glitch or anything.

Don't know the correlation myself except non-stock fuels.

[J_Davis]

It fired full upon igniting the staging and ignored throttle settings.

That part's intentional.

[Guest]

Yup. Real 1st stage engines also don't usually have a throttle. Unless it's a manned booster and you need to keep G-forces down, you don't need it.

[NathanKell]

Ferram: thanks much! Very helpful.

AdmiralTigerclaw: I have my ideas, now. And yes, limited throttling is intentional, as is (for SFJackBauer's RealEngines) not all engines being RF-enabled.

[ferram4]

More info on the symmetry tank-teleporting in orbit:

In my tests, if the tank hasn't had any fuel drawn from it the bug occurs; if fuel has been drawn from it, it loads fine. A RemoteTech relay that was headed for lunar orbit was (unfortunately) sacrificed for this information, so I hope it's helpful.

Edit: Nope, nvm that's not it. It does seem like a satellite that has no more stages is unaffected, but one that does have more stages is... basically, I didn't have that bug if I switched to a relay that had separated from its upper stage, but if the upper stage was still attached the bug occurred. Not sure what to make of that.

Edited January 1, 2014 by ferram4

[AdmiralTigerclaw]

"Many Kerbals died to bring us this information."

[Surefoot]

Got that funky behaviour too with a 8-symmetric NERVA booster: when used alone it's working as expected (put in orbit with hyperedit for example). But whenever i add a stage (for launch) or if i even dock something on it, then firing up the engines makes it rotate like crazy, as if it was totally unbalanced or a group of engines on one side was not properly working. I guess it's the same root cause, one side effect i noticed is Mechjeb's SmartASS fails to kill the rotation, for MJ it's as if there was no rotation to start with (with KILL ROT). Picking a fixed point like prograde works though and MJ will try and fight the rotation.

Also had this happen on my "Grand Tour" lander, 12 engines in pods of 3 in a 4x symmetry (these are the small 1.25m "orbital manoeuver" engines from Novapunch). Again, perfectly balanced, behaves nicely until i switch the view back and forth to it, then i cannot fire the engines or it will go in deadly rotation...

All of this, in orbit / vacuum.

(edit) using the latest MFS of course, and latest stretchytanks but without realfuels.

(edit2) screencap of both ships docked together (which produces the unintended behaviour):

(edit3) there seems to be a very slight unbalance to start with, even on first load, as mechjeb node execution will end up with the target moving out quickly with around 2-3m/s remaining (which means a little unbalanced thrust) - even with a perfectly balanced craft. Reloading / swapping POV seems to make things worse, but the situation exists from the start (or it's a MJ 2.1.1 glitch)

Edited January 2, 2014 by Surefoot

[ZacAttack42]

Seriously wtf is up with your SRBs? Am I the only one that gets 7-15 seconds out of them in all but ROv3pre2?

[NathanKell]

Ignoring for now the fact that it would be nice if you could ask politely, and that IIRC I already answered when you asked this before, I point to the fact that RF uses a real density for solid fuel, and that it enforces a 1 unit = 1 liter relationship. This means that to maintain burntime, your solid rockets should have 4.213483146x as many units of SolidFuel as they did before RF. The updated stockalike configs will do this (J_Davis has volunteered to make them, hurrah!), as does (as you see) my version of RO.

[ZacAttack42]

So its intentional that in the new RO SRBs dont have more fuel and therefore last only ~15seconds?

I know this mod uses liters, i am only asking about the srbs because i didnt see them mentioned anywhere in the op.

Edited January 3, 2014 by ZacAttack42

[NathanKell]

As stated above:

your solid rockets should have 4.213483146x as many units of SolidFuel as they did before RF. The updated stockalike configs will do this (J_Davis has volunteered to make them, hurrah!), as does (as you see) my version of RO.

[AdmiralTigerclaw]

In short. They're broken at the moment, and someone is working on them.

Be patient.

[ZacAttack42]

In short. They're broken at the moment, and someone is working on them.

Be patient.

Finally an answer. Thank you.

[AdmiralTigerclaw]

Finally an answer. Thank you.

He told you quite clearly. Slow down and process the details slick.

[J_Davis]

A picture

Please don't oversell me. XD

Edit:

If you use engines other than KW and Stock, please note me your perceptions of each engine and what kind of engine it is. I am guessing right now for making the stockalike file, and I really don't know what types of engines I'm looking at in most cases. Also, I want to share how I'm setting up the fuels. I'm using a system since the stockalikes are for gameplay, not realism. Please comment on the system I am using:

Type	Primary		Alternate	Tertiary	Mixture

L	Kerolox		NTO+MMH		NTO+Aerozine	Lean Mix
	KL		MMH		AZ		


L+	Kerolox		Hydrolox	NTO+MMH		Balanced
	KL		HL		MMH		


U	Hydrolox	NTO+MMH		UDMH+Nitric	Rich
	HL		MMH		UDA		


U+	Hydrolox	NTO+MMH		UDMH+Nitric	Very Rich
	HL		MMH		UDA		


O	NTO+MMH		Hydrolox	FOOF+H2S*	Extremely Rich
	MMH		HL		SHOES		


A	Kerolox		Hydrolox	Kerosene+HTP	Balanced
	KL		HL		KHP		


N	LH2		LCH4		LNH3
	NH		NM		NA		N/A

Edited January 3, 2014 by J_Davis
Request

[jrandom]

Will the next release perchance fix the Amines issue?

[NathanKell]

J_Davis: there's very little different between AZ50 and UDMH and MMH. I suggest only using 1 hydrazine-derivative per engine (MMH for O and U+, AZ50 or UDMH [depending on if US or non-US] for other engines). So I'd suggest replacing MMH with AZ50 (or UDMH) for U, and HTP/Kero for L. (and varying whether AZ50 or UDMH). Actually, you could just exclude MMH and AZ50 and always use UDMH. That probably makes the most sense from a gameplay standpoint. So definitely KHP for the third L fuel. Further, I'd ditch UDA in U for KL, and UDA in U+ for ML.

Oh lord really, FOOF? C'mon. Also do like "SHOES". Maybe AMA for the third O fuel? Or even HZ for a monopropellant engine?

jrandom: it was fixed when you told me about it and I released the next pre. The autoconfig button just rounds for display purposes; it will configure your tank correctly.

=======

As a holdover until stockalike is redone, I've at least fixed the solids so they have the same mass of solid fuel as stock KSP or MFS3.x.

[jrandom]

jrandom: it was fixed when you told me about it and I released the next pre. The autoconfig button just rounds for display purposes; it will configure your tank correctly.

It works with NitricAcid as the other component, but with Nitrous Oxide the Amines still show up as '0' with a resulting zero delta-v.

[NathanKell]

jrandom: download again ROv3pre2 (I don't think SFJackBauer uses any N2O/Amines engines, so it's just RftS that does them...). I just verified it's correct in the ROv3pre2 that's up there now. Maybe it you still had pre1, or maybe it was one of those things I fixed like 5 minutes later and you downloaded just before I fixed and reupped?

They will show as 0 on the button, but the tank should get like 0.03% Amines by unit ratio (which, considering N2O's utilization, will be a lot.)

[dlrk]

What exactly are nitric acid/amines?

[Guest]

Nitric acid was an early storable oxidizer, very early tech one. Similarily, amines were used as a corresponding fuel. Vostok used this configuration. Also, some early engines used nitric acid with UDMH, most notably on Agena upper stage.

Regarding hydrazine derivatives, it's a matter of stability. MMH gives the best Isp, but can't be used in large, regeneratively cooled engines, because it decomposes. UDMH can be used in much larger engines than MMH, but has a lower Isp. AZ-50 is in the middle, it's better than UDMH for medium-size engines, but can't be used for very large ones. Russians generally used UDMH as their storable fuel of choice, while Americans mostly used AZ-50, except a few cases where they used MMH.

In general, MMH should be mid-late tech fuel, with UDMH and AZ-50 being early-mid tech ones. Of those, UDMH would be acquired earlier and usable in larger engines than AZ-50.

Also, I'd like to note that there are two "kerosene substitutes" in MFS. Alcohol is an early-tech one and syntin is a late-tech one. They're used in the same engines as kerosene, but have different Isp.

Edited January 4, 2014 by Guest