[1.8+] Real Fuels

[PTNLemay]

Don't take this the wrong way, I love the mods you make and I appreciate all of the effort that you put into them, but... can I turn down the vapor in the feed lines thing?  Reduce the frequency at which it crops up.  Or just turn it off?  I'm willing to go into the ini files and edit things manually if I have to.

I recently fumbled a career mode in RP-0 (I accepted a Mars satellite mission, thinking I could accomplish it in time, and ended up going negative a million credits) so I wanted to try again.  Now I'm on a fresh career run, straight back at the start.  I forgot how omnipresent the vapor is early in the game it's quite a challenge.

Edited April 24, 2016 by PTNLemay

[NathanKell]

@PTNLemay sure, open RealFuels/RealSettings.cfg and look for simulate ullage (it's down near the bottom in the Ullage node). Set it equal to False rather than True. That will turn it off. Making it "easier" is much harder than that...

[Wolves_Hero]

I installed Real Fuel not worked on 1.1 can't choose fuel, I guess take long update feel 1 or 2 weeks.

[MarvinCZ]

7 hours ago, PTNLemay said:

Don't take this the wrong way, I love the mods you make and I appreciate all of the effort that you put into them, but... can I turn down the vapor in the feed lines thing?  Reduce the frequency at which it crops up.  Or just turn it off?  I'm willing to go into the ini files and edit things manually if I have to.

I recently fumbled a career mode in RP-0 (I accepted a Mars satellite mission, thinking I could accomplish it in time, and ended up going negative a million credits) so I wanted to try again.  Now I'm on a fresh career run, straight back at the start.  I forgot how omnipresent the vapor is early in the game it's quite a challenge.

Just in case, do you know how the vapor in feed lines happens and how to deal with it in-game? It sounds like you treat it as an engine failure, but it is caused by a temporary state of the engine and fuel system that is easily fixed.

From the first post:

Quote

* If ullage is enabled for the engine, and your propellant stability is not "Very Stable", there is a chance that vapor can get in the feed lines and the engine will flame out. You will need to set the throttle to 0 to reset things, then stabilize your propellants. Some forward RCS thrust, or thrust from ullage motors like small SRBs (solids and RCS aren't subject to ullage issues) will do that. Then you can try throttling the engine up again to restart it.

So, basically, if your engine is marked as not having its fuel stable (red / orange in the staging icons), give the rocket some forward thrust from RCS or SRBs. After a while of that thrust the fuel settles (the icon turns gray again) and you can start your engine. I usually keep the ullage thrust up until the engine is fully started, some can take a while.

If you know all this and just don't want to deal with it, I apologize.

Edited April 24, 2016 by MarvinCZ

[McKerbin]

On 4/24/2016 at 3:32 AM, MarvinCZ said:

Just in case, do you know how the vapor in feed lines happens and how to deal with it in-game? It sounds like you treat it as an engine failure, but it is caused by a temporary state of the engine and fuel system that is easily fixed.

From the first post:

So, basically, if your engine is marked as not having its fuel stable (red / orange in the staging icons), give the rocket some forward thrust from RCS or SRBs. After a while of that thrust the fuel settles (the icon turns gray again) and you can start your engine. I usually keep the ullage thrust up until the engine is fully started, some can take a while.

If you know all this and just don't want to deal with it, I apologize.

You can also use the over-powered stock reaction wheels to "cheat" if you don't have RCS or some sort of ullage motor.  Just rock you ship up and down or left/right and use the centrifugal force to push the fuel back to the engine.  I've used that several time when I forgot to plan for ullage on probes.

[Starwaster]

On 4/28/2016 at 1:02 PM, McKerbin said:

You can also use the over-powered stock reaction wheels to "cheat" if you don't have RCS or some sort of ullage motor.  Just rock you ship up and down or left/right and use the centrifugal force to push the fuel back to the engine.  I've used that several time when I forgot to plan for ullage on probes.

Unless of course one deliberately nerfs their reaction wheels even if not playing RO

[NathanKell]

v11.0

• Port to KSP 1.1, thanks to taniwha, Agathorn, Starwaster!
• Make sure clamps with the pump do pump EC even when the EC is not in a ModuleFuelTanks tank.
• Change boiloff to use wetted tank area and other boiloff improvements.
• Temprorarily remove TweakScale support until we can get it non-buggy.
• Infinite Propellants cheat now allows reignition even with no ignitions remaining / no ignitor resources remaining.

[Kussris]

Thanks NathanKell for all the work!

[OverNyanThousand]

On 4/28/2016 at 0:02 PM, McKerbin said:

You can also use the over-powered stock reaction wheels to "cheat" if you don't have RCS or some sort of ullage motor.  Just rock you ship up and down or left/right and use the centrifugal force to push the fuel back to the engine.  I've used that several time when I forgot to plan for ullage on probes.

 

Or you can get out and push... Wonder how many times NASA actually had to do this or similar KSPesque foolery to save a mission and never told anyone about it.

[Raptor831]

@NathanKell Thanks for the hard work, both here and on KSP in general.

Now I'm off to try everything out in 64-bit glory!

[SpaceEnthusiast]

This might be a stupid question, but is this mod the reason why my fuel ducts no longer pump fuel?

[NathanKell]

Nope.

10char

[Charlie the Kerbal]

On 4/23/2016 at 0:38 AM, PTNLemay said:

Don't take this the wrong way, I love the mods you make and I appreciate all of the effort that you put into them, but... can I turn down the vapor in the feed lines thing?  Reduce the frequency at which it crops up.  Or just turn it off?  I'm willing to go into the ini files and edit things manually if I have to.

I recently fumbled a career mode in RP-0 (I accepted a Mars satellite mission, thinking I could accomplish it in time, and ended up going negative a million credits) so I wanted to try again.  Now I'm on a fresh career run, straight back at the start.  I forgot how omnipresent the vapor is early in the game it's quite a challenge.

Hi PTNLemay,

My very similar initial response upon installing Real Fuels, I remember that I just wanted to check with the forum one last time before uninstalling it if there was a way to disable it. Then before even Nathan responded I noticed that it was manageable and actually making the game much more realistic. I must admit, after a while I went onto slightly modifying my copy of MechJeb to fire RCS for 6 seconds before maneuvers to ullage the fuel (but that was more to compensate my laid back gaming style where I was forgetting it all the time).

I'd say, give yourself some time.

[Starwaster]

3 hours ago, Charlie the Kerbal said:

Hi PTNLemay,

My very similar initial response upon installing Real Fuels, I remember that I just wanted to check with the forum one last time before uninstalling it if there was a way to disable it. Then before even Nathan responded I noticed that it was manageable and actually making the game much more realistic. I must admit, after a while I went onto slightly modifying my copy of MechJeb to fire RCS for 6 seconds before maneuvers to ullage the fuel (but that was more to compensate my laid back gaming style where I was forgetting it all the time).

I'd say, give yourself some time.

Even I was reluctant to use that feature when it first was put in, and I come down pretty firmly on the realism side. In the end, it's not that big a deal to deal with

Edited May 1, 2016 by Starwaster

[seamus2849]

I have installed this mod (direct from GitHub release v11.0), along with RSS, and RemoteTech. All mods are working great, except for RealFuels the engines still use LOX. The tanks can accept any fuel, but none of the engines took the new settings. Any ideas as to why?

 

***********SOLVED*************

Yea.... so.... found the problem... BTE... (Between the Ears).

Forgot to install the engine config. Working great now!

Edited May 2, 2016 by seamus2849
solved

[PTNLemay]

Yes eventually it's easier to manage, because like you said you can use RCS or other such systems to ensure the fuel will stabilize.  But early on it's just a beast to deal with.  The engines are super sensitive to the effect and there is no RCS to help.  Sometimes I don't know if I'm flying poorly, or if the mod is bugging out and giving me vapor when it never should have (it's probably the former).   Until I'm more skilled at these super realism thingies, I'll accept the gaming experience without it.

Edited May 2, 2016 by PTNLemay

[jstnj]

The ullage isn't my problem, how do you guys deal with 1 ingnition engines on the first two stages during early career? I can't correctly circularize and plan orbits when i can't completely shut down my 2nd stage.

[Dermeister]

HEy so  I know you can disable Ulage. But can you also Change options to disable Boil off and ignition limits?

[NathanKell]

@PTNLemay RCS is available in the start node. Further, ullage motors are available in the start node too.

To answer you and @jstnj here is what I do. (Note: This is basically copying what was done historically).

1. Either hotstage or use ullage motors for my second stage. If there is a third stage, it's probably solid, so ullage doesn't matter.

2. Fly a shallow enough gravity turn that I insert into orbit at my desired perigee (or thereabouts). That means making sure I don't go higher than 185km until all stages have done their work. Boosting to apogee and circularizing at apogee isn't just impossible with limited ignitions, it's inefficient. Any time spent not burning is time you're taking gravity losses you don't have to.

3. If I'm going beyond LEO, pack another stage (or use something with relights, like the AJ10-Mid or the later XLR81s or the 11D33M). Yes, this stage will need either ullage motors or RCS, but...they're both available in the starting node. Yes, you may have to use solids as kick motors, and that means you may not be able to do some things you'd like to. But remember: guided probes come in Stability/Early Probes, and that's not that far away.

 

Hotstaging is super simple: Just light up your next stage a second or three before the lower stage finishes burning. So are ullage motors: add some Inline Sep Motors around the base of your stage and fire them before igniting the stage.

 

One final note: Real life rockets don't tend to stage until outside the thicker parts of the atmosphere (say, no lower than 60km). If you're building something with A-4 engines (with their short burn times), you might not have that luxury, and then you'll really need to hotstage; ullage motors may not be enough. This is because you won't just be fighting the natural diffusion of the propellants after thrust goes away, you'll also be fighting aerodynamic drag, and going at, say, 1500m/s at only 25km...that's a lot of drag.

[CatastrophicFailure]

9 hours ago, Charlie the Kerbal said:

, after a while I went onto slightly modifying my copy of MechJeb to fire RCS for 6 seconds before maneuvers to ullage the fuel (

Ok, bit late to the game here, um.... how did you manage this??

[Adoelrome]

Tell me olease, can this mod replace Engine Ignitor which isn't supported from version 0,25?
I mean, restrictions for the number of starts of engines and an opportunity to recharge them?

[jstnj]

6 hours ago, Adoelrome said:

Tell me olease, can this mod replace Engine Ignitor which isn't supported from version 0,25?
I mean, restrictions for the number of starts of engines and an opportunity to recharge them?

Yes, it does

18 hours ago, NathanKell said:

@PTNLemay RCS is available in the start node. Further, ullage motors are available in the start node too.

To answer you and @jstnj here is what I do. (Note: This is basically copying what was done historically).

1. Either hotstage or use ullage motors for my second stage. If there is a third stage, it's probably solid, so ullage doesn't matter.

2. Fly a shallow enough gravity turn that I insert into orbit at my desired perigee (or thereabouts). That means making sure I don't go higher than 185km until all stages have done their work. Boosting to apogee and circularizing at apogee isn't just impossible with limited ignitions, it's inefficient. Any time spent not burning is time you're taking gravity losses you don't have to.

3. If I'm going beyond LEO, pack another stage (or use something with relights, like the AJ10-Mid or the later XLR81s or the 11D33M). Yes, this stage will need either ullage motors or RCS, but...they're both available in the starting node. Yes, you may have to use solids as kick motors, and that means you may not be able to do some things you'd like to. But remember: guided probes come in Stability/Early Probes, and that's not that far away.

 

Hotstaging is super simple: Just light up your next stage a second or three before the lower stage finishes burning. So are ullage motors: add some Inline Sep Motors around the base of your stage and fire them before igniting the stage.

 

One final note: Real life rockets don't tend to stage until outside the thicker parts of the atmosphere (say, no lower than 60km). If you're building something with A-4 engines (with their short burn times), you might not have that luxury, and then you'll really need to hotstage; ullage motors may not be enough. This is because you won't just be fighting the natural diffusion of the propellants after thrust goes away, you'll also be fighting aerodynamic drag, and going at, say, 1500m/s at only 25km...that's a lot of drag.

Great post @NathanKell, that's very helpful. Only one question: I see you posted 'LEO' in #3...does that mean these measurements are in RSS scale and not regular kerbin?

[NathanKell]

@jstnj Thanks! And yep. You don't need more than one stage if you're using RealFuels on regular Kerbin. :]

[Errol]

Is it possible to use this mod for only the ullage portion? I want to continue using stock engines and tanks, and stock-a-like part parts, but want to have limited ignitions and ullage requirements dependant on engine. It looks like engine ignitor is no longer being developed. 

[Starwaster]

40 minutes ago, Errol said:

Is it possible to use this mod for only the ullage portion? I want to continue using stock engines and tanks, and stock-a-like part parts, but want to have limited ignitions and ullage requirements dependant on engine. It looks like engine ignitor is no longer being developed. 

Engine Ignitor is built into Real Fuels now.

What you're asking is possible but you would have to remove Community Resources Pack, or at least override it by writing custom tank configs that revert back to using stock resources. And you would have to write up new engine configs or write an MM patch that configures the engines to support limited ignitions