[0.20] Modular Fuel System 1.3/realistic fuels, reconfigurable fuel tanks and engines

[Chingus]

I see that Kommitz has released a new version of his Fatman rockets, any tips on how to config them to work with this mod? http://forum.kerbalspaceprogram.com/showthread.php/26286-Nucleonics-Ltd-Rocketry-Division

[Starwaster]

I see that Kommitz has released a new version of his Fatman rockets, any tips on how to config them to work with this mod? http://forum.kerbalspaceprogram.com/showthread.php/26286-Nucleonics-Ltd-Rocketry-Division

You mean as in Real Fuels?

@PART[2mToroidFuOx]
{
	MODULE
	{
		name = ModuleFuelTanks
		volume = 400
		type = Default
	}
}

That adds the Modular Fuels module to the tank. Default tank type with volume 400 (the sum of its fuel capacities = 180 LF, 220 OX)

Seems kind of a dinky sized craft given that the engines in the pack are supposed to be nuclear? Assuming that they run on H2 which takes up a lot more space per KG than other fuels. It's the least dense of all the fuels.

To convert the actual engines, look in the the modular fuels folders for a file named Squad_modularEngines.cfg

Look for the entry on nuclearEngine and see how they changed the propellant. That's what you want to do to change it over so it uses LiquidH2. If you can't figure it out, I'll take a stab at converting it tomorrow as it's 5am and I'm tired here.

Edit: Hey Chingus, it looks like there's already support for the fatman engines. Do you have the very latest configs? Get them from Chestburster's signature, he's got a link there to the latest.

Edited August 24, 2013 by Starwaster

[Frederf]

0 Dry mass Squad fuselage tanks are a persistent issue even after applying the fix a few posts above. Dividing by zero is bad.

[steddyj]

So I've been having an issue with this and I haven't been able to figure it out. Some of the mods I use are not picking up the modifications. For instance, I can set values for tanks from KW, but not Spherical tanks. Also the modifications to the Kethane converter are not working. I have the cfg files for these mods but I can't figure out why some of them wont load.

[Starwaster]

0 Dry mass Squad fuselage tanks are a persistent issue even after applying the fix a few posts above. Dividing by zero is bad.

I don't think anyone actually posted a fuselage fix did they? .... some code was quoted illustrating some problems in the configs relating to mass but that's all that I know of.

Delete or undo whatever you applied before and create a file named fuselage_fix.cfg. Edit it and copy/paste the code below. That will give fuselage tanks mass specs equivalent to structural tanks. It's a quick and dirty hack so the mass might be too high. Or it might be just right, I'll have to look at it later.

fuselage_fix.cfg

// fuselage_fix.cfg
@TANK_DEFINITION[Fuselage]
{
	basemass = 0.0003125 * volume
	@TANK[LiquidFuel]
	{
		mass = 0.0003125
	}
	@TANK[Oxidizer]
	{
		mass = 0.0003125
	}
	@TANK[MonoPropellant]
	{
		mass = 0.0005
	}
	@TANK[XenonGas]
	{
		mass = 0.0005
	}
	@TANK[LiquidH2]
	{
	   mass = 0.00025
	} 
	@TANK[LiquidOxygen]
	{
	   mass = 0.0003125
	}
}

So I've been having an issue with this and I haven't been able to figure it out. Some of the mods I use are not picking up the modifications. For instance, I can set values for tanks from KW, but not Spherical tanks. Also the modifications to the Kethane converter are not working. I have the cfg files for these mods but I can't figure out why some of them wont load.

Double check ALL spherical tanks. The empty ones apparently don't have MF modules inserted into the code. Only the ones that come with fuel in them can be edited.

I don't know about the Kethane converter but I vaguely remember someone posting that they had fixed something, so look around for an alternate config. Maybe search this thread or the kethane thread.

Edited August 26, 2013 by Starwaster
Fixed cfg code. Thanks xZise

[xZise]

[…]Double check ALL spherical tanks. The empty ones apparently don't have MF modules inserted into the code. Only the ones that come with fuel in them can be edited.[…]

Afaik you don't need the empty ones when you have MF as you can empty an full tank.

By the way there is an error in the fix file you quoted: In th 5^th line is one opening bracket to much (before the LiquidFuel).

Fabian

[Chingus]

You mean as in Real Fuels?

Edit: Hey Chingus, it looks like there's already support for the fatman engines. Do you have the very latest configs? Get them from Chestburster's signature, he's got a link there to the latest.

Those appear to be for the "legacy" Fatman engines. They've been completely revamped. I suppose it wouldn't be too hard to edit the files.

[steddyj]

Yeah my issues with Spherical tanks were the empties. I deleted those from the cfg files. I'll have to search on the Kethane converter issue. Thanks for the help!

[Starwaster]

Afaik you don't need the empty ones when you have MF as you can empty an full tank.

True, but the point is that if he only checked the empty ones then it would logically appear that the spherical tanks are not working with this mod, which of course, they are.

By the way there is an error in the fix file you quoted: In th 5^th line is one opening bracket to much (before the LiquidFuel).

Fabian

Argh, thanks, I'll fix it.

[Starwaster]

Those appear to be for the "legacy" Fatman engines. They've been completely revamped. I suppose it wouldn't be too hard to edit the files.

LOL, you know what? When I said that, I'd checked that there was a fatman config file for Real Fuels, but not only that I'd looked in KSP itself and checked one of the engines (I downloaded it to check the engine out after you posted about it) and saw it was using LH2 so I assumed that the existing config file was already working with it.

What I had forgotten was that I had actually started prototyping out a config file for it and had saved it as a file so it was just picking up my changes...

[sirklick]

I had updated the Kethane config with this , but I am still unsure about the conversion values balance so left them as they were.

[Starwaster]

I had updated the Kethane config with this , but I am still unsure about the conversion values balance so left them as they were.

You never did get your discussion on balance figures did you?

FWIW, I think density needs to figure into it to make sure that you're not able to create huge quantities of some dense resource for lesser mass amounts of kethane. And that you can't likewise lose large amounts of resource. Maybe that's actually how it is; I've had Kethane installed for awhile now but STILL have not actually gotten to mine any kethane.... it's on my to do list.

[sirklick]

I have made very limited use of the Kethane mod as well. I did have a save with a Minmus fueling op for a short bit, but ultimately ended up rarely using it. Min/maxing rockets for specific payloads is enough fun that I don't actually get out there and explore as much as I probably should. That being said, I did do a quick study of the Kethane numbers and they are not as crazy as I originally may have thought.

The algorithm that Kethane uses for computing output of fuel per unit of Kethane is inputDensity/outputDensity*outputRatio. The only values to set are the input units, energy expenditure, and the output ratio. Perhaps I am slightly masochistic but my first inclination in attempting to find the proper balance was to look at the chemical composition of each of the output fuels and come to some possible real world analog for Kethane. It did not take too long for me to realize how futile and yes stupid this approach was. Within the realm of the Realistic Fuels mod Kethane is a magical petrochemical slurry and Kerbins are crazy advanced in chemistry and chemical breakdown/assembly.

So with realism mostly out of the door, my thought is that convenience may be the best way to balance the numbers. LH2/LOX mix ratio is 73/27 or some such right? Since Kethane allows you to convert to multiple fuels at once, why not set the input values so that the output is of at least roughly that ratio assuming LH2 and LOX conversion are running at the same time. This seems to be the Method Majiir is using for the stock fuels.

[bs1110101]

How can i make a nuclear powered spacecraft that has the same kind of delta v that a stock one would have without just stacking tanks until i have the thrust to weight ratio of an ion drive?

[Starwaster]

How can i make a nuclear powered spacecraft that has the same kind of delta v that a stock one would have without just stacking tanks until i have the thrust to weight ratio of an ion drive?

Liquid H2 only weighs 70kg /m3. Use the cryogenic tanks, they're slightly less massive. The big orange one is cryo.

[bs1110101]

That helps, though not all the much, ether someone forgot a zero, or i should make configs for the fatman ntrs to act as open cycle gas core ntrs so i have something powerful and not quite as op as the orion drive. Somewhat relatedly, does anyone know the ratio of hydrogen to uranium hexafluoride in one of those, and is there a way to add a new type of fuel to all the tanks at once?

[Starwaster]

That helps, though not all the much, ether someone forgot a zero, or i should make configs for the fatman ntrs to act as open cycle gas core ntrs so i have something powerful and not quite as op as the orion drive. Somewhat relatedly, does anyone know the ratio of hydrogen to uranium hexafluoride in one of those, and is there a way to add a new type of fuel to all the tanks at once?

If you use the ModuleManager Extensions (by Sarbian) you could use wildcards... I think.

Otherwise, no. But it's not hard to do them one at a time too. But should uranium hexafluoride really be a tank resource? Anyway, below is how it's done.

@TANK_DEFINITION[Default]
{
	TANK
	{
		name =  UraniumHexaFluoride // Hope you defined this as a resource too
	}
}
@TANK_DEFINITION[Cryogenic]
{
	TANK
	{
		name =  UraniumHexaFluoride // Hope you defined this as a resource too
	}
}
// Rinse and repeat until you're done.

Uranium ratio might be as high as 1%

Check this out:

http://www.academia.edu/1705932/Nuclear_Power_and_Nuclear_Propulsion_Applications_in_Space

You'll have to search a bit for gas core rockets. In a couple of places he indicates that uranium consumption is at about 1% but in one spot it's listed as 1/1000th of H2 mass flow. Unless mass flow means something different than what I'm interpreting?

BTW, you can still bump up ISP for the stock NTR rockets a bit and still stay realistic.

Edited August 29, 2013 by Starwaster

[bs1110101]

You have a point about not making it a tank resource, i might make it need to be in special tanks that don't hold that much of it so that they aren't quite as useful as a normal rocket with that kind of isp, I might also make them not able to be throttled much if at all.

What i'm thinking to do is to have them as very powerful, but inefficient with uranium so that they're balanced against the solid core ntrs which are less efficient with hydrogen, but more efficient with uranium.

I might also rebalance the stock ntrs if someone hasn't done it before i had the chance, also, we should be able to use denser propellants in ntrs like this www.astronautix.com/fam/yardicbm.htm#more , though that wouldn't be all that useful unless you can reconfigure them once in orbit, so, for that i'm waiting on the plug in devs.

Edit! They're going to use 3 to .5 percent by volume, and will get more efficient as they get bigger, uranium hexafluoride will only come in small, heavy, or oddly shaped tanks so it cant go critical in the tanks. Here's a mock up of what it should look like when done.

Something like that should have about 10 kps of delta v in hydrogen and enough uranium hexafluoride for 3 or 4 refuels before it's out. (Note: these are guesses based on what i think would be balanced, and are likely very far off.)

Edited August 29, 2013 by bs1110101

[Starwaster]

You have a point about not making it a tank resource, i might make it need to be in special tanks that don't hold that much of it so that they aren't quite as useful as a normal rocket with that kind of isp, I might also make them not able to be throttled much if at all.

What i'm thinking to do is to have them as very powerful, but inefficient with uranium so that they're balanced against the solid core ntrs which are less efficient with hydrogen, but more efficient with uranium.

I might also rebalance the stock ntrs if someone hasn't done it before i had the chance, also, we should be able to use denser propellants in ntrs like this www.astronautix.com/fam/yardicbm.htm#more , though that wouldn't be all that useful unless you can reconfigure them once in orbit, so, for that i'm waiting on the plug in devs.

I dont think ANY of the real world NTRs are throttleable. Also after reading up some more on UHF, it may well be tankeable after all. However, The Atomic Rocket site says that fluorine gas is a byproduct and quotes one chemist as having said that at high temperatures, fluorine loses its gentle and forgiving nature. (sarcasm)

on the subject of other NTR propellents, I've been working on some configs that add new propellents. I'm reluctant to release them yet because most of the numbers came from the Atomic Rocket site, and while I generally trust that site, after running the numbers, I'm starting to question their validity, especially at the cited temperatures of 3200K. For instance they give an exhaust velocity of 8,093 m/s which comes out to an Isp of about 825, which strikes me as way too low. real world examples from the late 60s did better with isp of 850... with a reactor temp of (I think) 2500. the whole thing has left me frustrated as I try to work it out and finding multiple variables that I dont know if I'm handling them right. Worse is I actually havent played in two days which is what Id rather be doing. I take back what I said earlier about math. I'm mreally hating math right now

[bs1110101]

The math is making my head hurt too, and is kinda stopping me from making this work right now.

Also, about fluorine, i think the best way to do it is try to make the fluorine get thrown out with the exhaust without touching the chamber walls much, though i doubt this matters for ksp.

Edit! I'v got one of the engines done, though i have no idea how to add a new resource with this thing.

Edit! Again! Why is the formatting for some of the files messed up, and how do i fix it?

Edited August 29, 2013 by bs1110101

[Starwaster]

The math is making my head hurt too, and is kinda stopping me from making this work right now.

Also, about fluorine, i think the best way to do it is try to make the fluorine get thrown out with the exhaust without touching the chamber walls much, though i doubt this matters for ksp.

Edit! I'v got one of the engines done, though i have no idea how to add a new resource with this thing.

Edit! Again! Why is the formatting for some of the files messed up, and how do i fix it?

The following code is how I added water.

Density should be set to the resource's mass in metric tons per liter * 6.25

Water weighs 1 kg per liter so 0.001 * 6.25 = 0.00625

RESOURCE_DEFINITION
{
	name = LiquidH2O // Primarily as a test article. Potential nuclear fuel but has poor performance characteristics. Or does it?
	density = 0.00625
	flowMode = STACK_PRIORITY_SEARCH
	transfer = PUMP
}

[bs1110101]

That's kinda hard to do, look what my files look like!

// all density units are in kg per Kerbo (1 Kerbo =  6.25 cubic meters)

@RESOURCE_DEFINITION[LiquidFuel]
{
  @density = 0.005 // this is remarkably close to the density of RP-1
}

@RESOURCE_DEFINITION[Oxidizer]
{
  @density = 0.008 // We'll assume that 'Oxidizer' is pure (95%) Hydrogen Peroxide
}

@RESOURCE_DEFINITION[MonoPropellant]
{
  @density = 0.004 // given RCS Isp, this is probably Hydroxylammonium Nitrate.
}

RESOURCE_DEFINITION
{
  name = LiquidH2
  density = 0.00045 // LH2 is super-light
  flowMode = STACK_PRIORITY_SEARCH
  transfer = PUMP
}

RESOURCE_DEFINITION
{
  name = LiquidOxygen
  density = 0.007 // Liquid Oxygen is lighter than H2O2, but tends to give higher Isp
  flowMode = STACK_PRIORITY_SEARCH
  transfer = PUMP
}

RESOURCE_DEFINITION
{
  name = nuclearFuel // Uranium-235
  density = 0.02
  flowMode = NO_FLOW
  transfer = NONE
}

RESOURCE_DEFINITION
{
  name = nuclearWaste // spent Uranium + contaminates
  density = 0.02
  flowMode = NO_FLOW
  transfer = NONE
}

@RESOURCE_DEFINITION[XenonGas]
{
  @density = 0.0003
}

Now i paste it here and it's fixed, in the text files it's all in 2 very long lines!

[Starwaster]

That's kinda hard to do, look what my files look like!

// all density units are in kg per Kerbo (1 Kerbo =  6.25 cubic meters)

@RESOURCE_DEFINITION[LiquidFuel]
{
  @density = 0.005 // this is remarkably close to the density of RP-1
}

@RESOURCE_DEFINITION[Oxidizer]
{
  @density = 0.008 // We'll assume that 'Oxidizer' is pure (95%) Hydrogen Peroxide
}

@RESOURCE_DEFINITION[MonoPropellant]
{
  @density = 0.004 // given RCS Isp, this is probably Hydroxylammonium Nitrate.
}

RESOURCE_DEFINITION
{
  name = LiquidH2
  density = 0.00045 // LH2 is super-light
  flowMode = STACK_PRIORITY_SEARCH
  transfer = PUMP
}

RESOURCE_DEFINITION
{
  name = LiquidOxygen
  density = 0.007 // Liquid Oxygen is lighter than H2O2, but tends to give higher Isp
  flowMode = STACK_PRIORITY_SEARCH
  transfer = PUMP
}

RESOURCE_DEFINITION
{
  name = nuclearFuel // Uranium-235
  density = 0.02
  flowMode = NO_FLOW
  transfer = NONE
}

RESOURCE_DEFINITION
{
  name = nuclearWaste // spent Uranium + contaminates
  density = 0.02
  flowMode = NO_FLOW
  transfer = NONE
}

@RESOURCE_DEFINITION[XenonGas]
{
  @density = 0.0003
}

Now i paste it here and it's fixed, in the text files it's all in 2 very long lines!

Use Notepad++

I will NEVER use anything else ever again. Especially not ever.

Also, don't edit the mod files. That defeats the purpose of them having used Module Manager in the first place

Create your own CFG files. Possibly you might need to make sure that the file name is alphabetically last Or failing that use the :Final keyword (Final makes sure that the config is processed dead last but my gut says not to if you intend to distribute your files as I intend to when I nail down my NTR mode and propellent additions.

[bs1110101]

Notepad++ is a good tip, i'll use that from now on, and i will write new files. Also, does anyone care about the old fatman ntrs?

[Starwaster]

Notepad++ is a good tip, i'll use that from now on, and i will write new files. Also, does anyone care about the old fatman ntrs?

personally I havent decided yet. they look neat but I've been feeling the effects of too many parts lately so they might have to go