[1.8+] Real Fuels

[Starwaster]

On 8/8/2016 at 11:41 AM, FreeThinker said:

yes, for MPD the Isp would be 14.4% of Hydrogen and for VASMIR the ISP something similar to Oxygen. not that high, but the biggest advantage would be the high storage density.

Edit: at second view, this stuff is a solid, I don't think it will work in a MPD, which can only work with gases, you would need to convert in to gas first.

I think the actual resource originally asked about was AF-M315E which is a liquid. (HAN is only one of its components)

[Emirhan]

Engines are automaticly shut down at half fuel!! Help!

Also it say's stable propellant! Is this a bug???

Edit: Never mind. I don't look test flight.

Edited August 13, 2016 by Emirhan

[Treble Sketch]

Well, just figured out today that this mod is incompatible with the Launcher's Pack SpaceX engines.

As seen in this post I made a while ago, 

 

And today, after some quick testing I can confirm that Real Fuels is the cause of the error. I am not currently sure what goes on behind the scene here with engine's fuel intake being changed/parsed via ModuleManager. I haven't looked into the process of making an engine compatible with RF, but I did ask the original developer if they can have a look at it.

Thanks though, you all go and have yourself a great day

[Starwaster]

8 hours ago, Treble Sketch said:

Well, just figured out today that this mod is incompatible with the Launcher's Pack SpaceX engines.

As seen in this post I made a while ago, 

Thanks though, you all go and have yourself a great day

Thanks for the feedback but two things:

1. There's not enough information in your posts to go on.
2. Real Fuels does not itself modify any engines by itself. That would necessarily be done by another mod / set of configs that that you have installed. If you upload your output_log.txt file or player.log (if Linux/Mac), post the link to where the files can be downloaded I'll take a look at it and tell you where that's being done. (More than likely, the person(s) responsible for the mod that applied RF configs to your engines and/or tanks would need to fix their configs)
3. For uploading logs I recommend dropbox. No screenshots of portions of the log either. Actual log file. Thank you!

Edited August 19, 2016 by Starwaster

[Ralathon]

Hey Nathan. Something is definitely iffy with tweakscale + RF integration.

So far I've narrowed it down to a small tank (Oscar B tank) rescaled to 0.4m going NaN when drained to about 50%. Before draining to that point everything works just fine. Tested on an install containing RSS (Shouldn't affect stuff), Engineer (shouldn't affect stuff), Procedural fairings (again, no influence), Ven's stock revamp (for the eyecandy) and of course Realfuels + tweakscale.

Here's a copy of my log in which I discovered said bug. The relevant bit is this stuff here:

  Hide contents

[F: 154145]: [02:46:59]: [00:46:59] <color=orange>[LV-1 "Ant" Liquid Fuel Engine]: vapor in feedlines, shut down!</color>
 
(Filename: C:/buildslave/unity/build/artifacts/generated/common/runtime/UnityEngineDebugBindings.gen.cpp Line: 64)

RCS lock/unlock
 
(Filename: C:/buildslave/unity/build/artifacts/generated/common/runtime/UnityEngineDebugBindings.gen.cpp Line: 64)

[ModularFlightIntegrator] MFI Start
 
(Filename: C:/buildslave/unity/build/artifacts/generated/common/runtime/UnityEngineDebugBindings.gen.cpp Line: 64)

[ModularFlightIntegrator] Start. VesselModule on vessel : 
  ModularFlightIntegrator
  UllageModule
  SolverFlightSys

 
(Filename: C:/buildslave/unity/build/artifacts/generated/common/runtime/UnityEngineDebugBindings.gen.cpp Line: 64)

recalculating orbit for fuelTankSmallFlat: the Moon ( Update mode TRACK_Phys )
rPos: [NaN, NaN, NaN]   rVel: [NaN, NaN, NaN] |NaN|
 
(Filename: C:/buildslave/unity/build/artifacts/generated/common/runtime/UnityEngineDebugBindings.gen.cpp Line: 64)

recalculated orbit for fuelTankSmallFlat: the Sun ( UT: 2197517.37348446 )
rPos: [NaN, NaN, NaN]   rVel: [NaN, NaN, NaN] |NaN|
Delta: [NaN, NaN, NaN] / [NaN, NaN, NaN]
 
(Filename: C:/buildslave/unity/build/artifacts/generated/common/runtime/UnityEngineDebugBindings.gen.cpp Line: 64)

[F: 154641]: RCSBlock collided into fuelTankSmallFlat - relative velocity: NaN - impact momentum: NaN
 
(Filename: C:/buildslave/unity/build/artifacts/generated/common/runtime/UnityEngineDebugBindings.gen.cpp Line: 64)

RCSBlock Exploded!! - blast awesomeness: 0.5
 
(Filename: C:/buildslave/unity/build/artifacts/generated/common/runtime/UnityEngineDebugBindings.gen.cpp Line: 64)
 

After that first mention of a NaN everything predictably goes to excrements as the NaN spreads throughout the ship and demolishes everything. Considering that the bug only occurs when the tanks start to empty means it's probably something with the mass going to 0.

Looking at the offending tank in the VAB with engineer you can see this is indeed the case

In fact, testing it with several other tanks shows that many of the smaller tanks go negative mass when scaled down. Definitely something not working correctly here.

 

Edit: Just tested with a completely barebones install. Only tweakscale as it comes out of the box, Realfuels as it comes out of the box (no engine configs) and Engineer to see masses. Negative mass problem persists when downscaling tanks.

Edited August 20, 2016 by Ralathon

[Kerbal01]

Could a GO2/GH2 resource be added? Want to make a reasonable replica of the ACES stage from Vulcan in RSS/RO and it uses boiloff GH2/GO2 RCS instead of hydrazine 

[Treble Sketch]

@Starwaster Uploaded everything that I think would be needed along with a screenshot that the game stays stuck at.

https://www.dropbox.com/sh/dsj0ztp6rt74gm7/AACo_6V_6vWjOxK8dkWiWQfAa?dl=0

[Starwaster]

On 8/20/2016 at 6:35 AM, Ralathon said:

Hey Nathan. Something is definitely iffy with tweakscale + RF integration.

So far I've narrowed it down to a small tank (Oscar B tank) rescaled to 0.4m going NaN when drained to about 50%. Before draining to that point everything works just fine. Tested on an install containing RSS (Shouldn't affect stuff), Engineer (shouldn't affect stuff), Procedural fairings (again, no influence), Ven's stock revamp (for the eyecandy) and of course Realfuels + tweakscale.

Here's a copy of my log in which I discovered said bug. The relevant bit is this stuff here:

  Reveal hidden contents

[F: 154145]: [02:46:59]: [00:46:59] <color=orange>[LV-1 "Ant" Liquid Fuel Engine]: vapor in feedlines, shut down!</color>
 
(Filename: C:/buildslave/unity/build/artifacts/generated/common/runtime/UnityEngineDebugBindings.gen.cpp Line: 64)

RCS lock/unlock
 
(Filename: C:/buildslave/unity/build/artifacts/generated/common/runtime/UnityEngineDebugBindings.gen.cpp Line: 64)

[ModularFlightIntegrator] MFI Start
 
(Filename: C:/buildslave/unity/build/artifacts/generated/common/runtime/UnityEngineDebugBindings.gen.cpp Line: 64)

[ModularFlightIntegrator] Start. VesselModule on vessel : 
  ModularFlightIntegrator
  UllageModule
  SolverFlightSys

 
(Filename: C:/buildslave/unity/build/artifacts/generated/common/runtime/UnityEngineDebugBindings.gen.cpp Line: 64)

recalculating orbit for fuelTankSmallFlat: the Moon ( Update mode TRACK_Phys )
rPos: [NaN, NaN, NaN]   rVel: [NaN, NaN, NaN] |NaN|
 
(Filename: C:/buildslave/unity/build/artifacts/generated/common/runtime/UnityEngineDebugBindings.gen.cpp Line: 64)

recalculated orbit for fuelTankSmallFlat: the Sun ( UT: 2197517.37348446 )
rPos: [NaN, NaN, NaN]   rVel: [NaN, NaN, NaN] |NaN|
Delta: [NaN, NaN, NaN] / [NaN, NaN, NaN]
 
(Filename: C:/buildslave/unity/build/artifacts/generated/common/runtime/UnityEngineDebugBindings.gen.cpp Line: 64)

[F: 154641]: RCSBlock collided into fuelTankSmallFlat - relative velocity: NaN - impact momentum: NaN
 
(Filename: C:/buildslave/unity/build/artifacts/generated/common/runtime/UnityEngineDebugBindings.gen.cpp Line: 64)

RCSBlock Exploded!! - blast awesomeness: 0.5
 
(Filename: C:/buildslave/unity/build/artifacts/generated/common/runtime/UnityEngineDebugBindings.gen.cpp Line: 64)
 

After that first mention of a NaN everything predictably goes to excrements as the NaN spreads throughout the ship and demolishes everything. Considering that the bug only occurs when the tanks start to empty means it's probably something with the mass going to 0.

Looking at the offending tank in the VAB with engineer you can see this is indeed the case

In fact, testing it with several other tanks shows that many of the smaller tanks go negative mass when scaled down. Definitely something not working correctly here.

Pinging @NathanKell to make sure he sees this. Both modules have GetModuleMass(). Just a thought but together they're both shaving some mass off. If we can detect that TS is installed, maybe not factor in the base tank cost and only use the mass of the individual TANK...?

1 hour ago, DarthVader said:

Could a GO2/GH2 resource be added? Want to make a reasonable replica of the ACES stage from Vulcan in RSS/RO and it uses boiloff GH2/GO2 RCS instead of hydrazine 

Those resources exist as Oxygen and Hydrogen and are boiloff products if some sort of surge or sump tank is present. At some point in future I'd like to maybe do a virtual resource request against the ullage gas... (currently boiloff product is ONLY done on ServiceModule parts because it does deduct from the boiloff mass which is used for ullage control)

50 minutes ago, Treble Sketch said:

@Starwaster Uploaded everything that I think would be needed along with a screenshot that the game stays stuck at.

https://www.dropbox.com/sh/dsj0ztp6rt74gm7/AACo_6V_6vWjOxK8dkWiWQfAa?dl=0

I'll look at it later, going to eat now.

[SpacedInvader]

So I'm returning to the game after an unwanted break and in the process of setting everything up again (always the worst part, right?)... anyway, this time around I am planning on running RF + stock Kerbol using the ~1/3 isp values rather than setting "useRealisticMass = false" to try and get something more akin to proper scaled performance. Now that we have MM math, I am trying to use a catch-all config for the change rather than trying to go through an do each by hand, but i just wanted to be sure I've got it written correctly before I get into the game and start beating my head against an invisible wall. Can someone with better config chops than me have a look and tell me if it will accomplish what I'm hoping it will?

@PART[*]:HAS[@MODULE[ModuleEngineConfigs]]:FINAL
{
 @MODULE[ModuleEngineConfigs]
 {
  @CONFIG,*
  {
   @IspSL *= 0.35
   @IspV *= 0.35
  }
 }
}

Also, will these reduced Isp values give me Earth scale rockets or Kerbin scale rockets, just with proper proportions? 

Thanks.

Edited August 25, 2016 by SpacedInvader

[John FX]

Would this be the right place to ask about liquid oxygen boiloff while on the pad?

I would have thought that while on the pad and connected to a launch stability enhancer that my craft would have a feed to keep the cryo liquids topped up.

As it is, if I need to warp to the correct launch window my craft boils off liquid oxygen.

Is this the correct function intended for cryo liquids?

[Phineas Freak]

@John FX did you activate the fuel pumps of the launch clamps? Right - click on them and select "Activate Fuel Pump" if you haven't done so.

[John FX]

2 minutes ago, Phineas Freak said:

@John FX did you activate the fuel pumps of the launch clamps? Right - click on them and select "Activate Fuel Pump" if you haven't done so.

Ah, didn`t realise there was a right click menu for clamps. Thank you very much for letting me know.

[manulemaboul]

nevermind, I'm stupid

Edited September 7, 2016 by manulemaboul
my own stupidity

[Starman4308]

On 8/12/2016 at 6:34 AM, Starwaster said:

Why not this?

 

At least from the perspective of a relatively casual player: mostly because it exists as a GitHub repo with no installation instructions, with the last commit six months ago, and no mention whatsoever about 1.1.2 or 1.1.3 compatibility. I know it's kind of a band-aid fix (Karbonite assumed to be whatever combination of NH3, H2O, and CO2 it needs to be), but I did develop a Karbonite config here:

On 9/25/2016 at 0:18 AM, Starman4308 said:

Alrighty. Sounds to me then like I should make the default hydrolox config dump LO2 (for some reason, the engine configs use ~3x more LH2 than LO2, when comparing on densities, it should be ~2x), and then have the hypergolic configs dump the byproduct (usually LH2 or LO2).

Testing is going well: it behaves as expected. The only thing I can't test is the CO production of the "real methalox" config, because procedural fuel tanks don't have any config for CO. While I'm at it, I'll polish things off with configs for a few of the easy-to-make molecules like methanol, H2O2, etc.

Maybe a spirit-of-the-mod question: is Karbonite meant to be a very raw resource? Right now, I have Karbonite -> fuel production being 80% mass-efficient (though that's 80% with byproducts, such as MMH/UDMH producing LqdOxygen), and I'm wondering if that should be tweaked down.

EDIT: If you want to try it out, let me know if this DropBox link works. Sorry about not putting it as a pull request on GitHub, I've just had GitHub issues (can't have a separate account for professional vs. KSP work).

https://www.dropbox.com/s/1byx3p67f38vvxb/KA-RealFuels.cfg?dl=0

The spreadsheet, for whoever wants to check my work:

https://www.dropbox.com/s/09e08kp5qey2g17/Spreadsheet.xlsx?dl=0

 A question I wanted to ask quick: is the reason that most of the hydrolox configs run hydrogen-rich (by molar rate, not by mass) because hydrogen is a nice, lightweight gas to be throwing out the exhaust (higher velocity at given temperature), and complete combustion would lead to excessive combustion chamber temperatures?

[YauS]

How to enable crossfeed for radial attached part?

[Northstar1989]

Hey, I know I asked about this a long time ago when I didn't understand/remember that all commonly used cryogenic propellants (and indeed, nearly all liquids) are incompressable, but why are we assuming that all fuel tanks are at 1 atm pressure?  Is that necessarily the case for all propellant tanks not pressurized in order to fuel pressure-fed rocket engines (which mods we have represented as service modules)?

What I was thinking, specifically, is that looking at temperature-pressure curves it's possible to keep certain propellants with higher boiling-points (cryogenics with higher molecular mass like Oxygen, or most hypergolics) in liquid form at significantly lower pressures by cooling them to even lower temperatures.  Conversely, you can keep them liquid at higher temperatures by keeping them pressurized above 1 atm.

I know that none of this affects the density of the propellants to any significant degree, but it DOES affect the thermal insulation and tank-mass situation.

Specifically, some propellants with very low boiling points like LH2 might be worth keeping pressurized above 1 atm to cut back on the need for thermal insulation a bit (although this may of course cost you in higher tank mass), while other propellants with higher boiling points like hypergolics or water (which you sometimes have to actively WARM to keep from freezing) might be worth keeping at lower pressures to save on fuel tank mass and slightly reduce the need to actively warm them to avoid freezing...

I mean, a tank of hypergolics pressurized to only 0.5 atm should theoretically only require half the tank-mass in vacuum of a tank at 1 atm- although of course you'd still need a tank strong enough to withstand stresses during launch.

Let me know what I'm missing here, or why we automatically assume none of our propellants might not be kept at lower pressure (down to 0.5 atm- where the inwards pressure at sea-level roughly equals the outwards pressure in vacuum) to save, at least slightly, on tank mass...

 

Regards,

Northstar

Edited October 8, 2016 by Northstar1989

[Northstar1989]

On Monday, September 26, 2016 at 10:11 PM, Starman4308 said:

A question I wanted to ask quick: is the reason that most of the hydrolox configs run hydrogen-rich (by molar rate, not by mass) because hydrogen is a nice, lightweight gas to be throwing out the exhaust (higher velocity at given temperature), and complete combustion would lead to excessive combustion chamber temperatures?

Yes and yes.  In fact one reason the Russians historically used O2-rich combustion in many of their engines, but we went fuel-rich, was because Russian metallurgical techniques were well ahead of our own and they could make engine chambers that could withstand much higher chamber pressures and temperatures than we could (complete combustion leads to higher chamber pressures and hotter combustion chambers).

Eventually we caught up to the Russians in terms of metallurgy, but we stuck with our legacy of developing fuel-rich rocket engines, especially with HydroLox- where the low molecular mass of H2 really does yield some nice ISP benefits (but much lower propellant-density for your rocket...)

The higher chamber pressures of going O2-rich also lead to higher exhaust-pressures with the same expansion-ratio, and thus less of a penalty to your sea-level ISP.  And, since LOX is less deeply cryogenic than LH2, you don't need to insulate it as heavily, which saves on mass.

Really, given that one of the most important drivers of launch costs is ground logistics and launchpad setup-time (and rockets with higher propellant-density are smaller and therefore easier to handle) and the size of the launchpads limit the size of the rockets you can launch, we would probably be better off with O2-rich engines for our launch-stages (but fuel-rich upper stage engines).  But given our engineering legacy in going fuel-rich, it's no surprise we continue with such engines, despite the obvious benefits of going O2-rich for launch stages...

 

Regards,

Northstar

Edited October 8, 2016 by Northstar1989

[blowfish]

@Northstar1989 I think it has to do more with fuel choice and cycle than fuel vs oxidizer rich.  The Russians developed a lot of kerolox staged combustion engines - you can't do fuel rich staged combustion with kerosene.  If you look at hydrolox staged combustion engines, they are all (AFAIK) fuel rich regardless of who built them.

Edited October 8, 2016 by blowfish

[Lexx Thai]

Any news about KSP 1.2 support?

[fallout2077]

On 10/19/2016 at 1:36 PM, Lexx Thai said:

Any news about KSP 1.2 support?

NathanKell posted in another thread (I believe it was the FAR thread) that he would taking a break for a while, as the crunch for 1.2 was a bit taxing.

Nope, it wasn't the thread for FAR. I'll try to find it and link to it.

 

 Here it is:

 

Edited October 20, 2016 by fallout2077
Posted associated post.

[michal.don]

Hi,

I have an issue concerning Liquid hydrogen boiloff. I am playing a 1.1.3 RO/RP-0 carrer, and I'm designing a 3-man spacecraft for LEO/Munar operations lasting about 10 days. I need three fuel cells to produce enough electricity, and their description says they should need about 41 litres of LH2 a week, each, including boiloff. So that should be around 150 litres. But in my test flights the LH2 disappears much faster. I found out I need almost ten times that much, just to keep my fuel cells running. I am using cryogenic tanks, and I tried to shape them to minimize the surface/volume ratio.

The orange tanks are all just for LH2/LOX, and it is still not enough. What am I missing?

Thanks,

Michal.don

 

[Starwaster]

7 hours ago, michal.don said:

Hi,

I have an issue concerning Liquid hydrogen boiloff. I am playing a 1.1.3 RO/RP-0 carrer, and I'm designing a 3-man spacecraft for LEO/Munar operations lasting about 10 days. I need three fuel cells to produce enough electricity, and their description says they should need about 41 litres of LH2 a week, each, including boiloff. So that should be around 150 litres. But in my test flights the LH2 disappears much faster. I found out I need almost ten times that much, just to keep my fuel cells running. I am using cryogenic tanks, and I tried to shape them to minimize the surface/volume ratio.

The orange tanks are all just for LH2/LOX, and it is still not enough. What am I missing?

Thanks,

Michal.don

 

Use Service Module tanks instead.

But also be careful about taking those claims as to quantity and boiloff  at face value. Who knows under what circumstances those figures were derived.

(now that RF supports boiloff gas product, they should probably reconfigure those fuel cells anyway to take advantage)

[michal.don]

10 hours ago, Starwaster said:

Use Service Module tanks instead.

Oh, apparently, you are right. I did some testing, and the service module tanks perform much, much better.

while the service module lost about 16% of LH2 in ten-ish days, the cryogenic tank lost more than 78%!

That leaves me curious, what is the point of cryogenic tanks, when their cooling abilities are this bad? Isn't the better cooling the purpose of these tanks 

Thanks,

Michal.don

[Phineas Freak]

1 hour ago, michal.don said:

Isn't the better cooling the purpose of these tanks 

Yes and no. They are better than the rest of the tank types (excluding the "ServiceModule" type) for keeping cryogenics in liquid state but they are not meant for long term storage. Think of it like the Space Shuttle ET or the Delta IV CBC tankages.

Try the same thing that you did but this time comparing the "Default" and the "Cryogenic" types and you will see.

[Starwaster]

@michal.don

@Phineas Freak

the reason service module tanks are so much better is vacuum walled vapor cooled non integrated tanks. Realistically there should be size limits and cost issues with making them as full sized stage tanks. Maybe some day that will happen. 

 

Cryotanks also have MLI that would require fairings to protect them. 

Terse reply on phone and about to vote . Will answer More later if more questions. 

Edited October 24, 2016 by Starwaster