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

ialdabaoth

By ialdabaoth
in KSP1 Mod Releases

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s20dan

s20dan

Posted
Posted (edited)
I didn't check it with my own calculations, but I guess it's because of the additional dry mass. You could test if you add enough fuel to the LF/OX combination which isn't LF/OX so that the dry mass (the mass of the tank fully fuelled except for LF and OX) is about the same dry mass as the LF/LOX tank.

Or another possibility is, that KER/MJ don't really bother what type of fuel you use. So if you fill the tank only with LF if KER and MJ still calculate the ÃŽâ€v as if you could use all LF (what you can obviously as oxidizer is missing).

At the moment I can't test it on my own so I can only suggest.

Fabian

You're correct. I neglected to account for tank dry mass as I had checked with LF/OX and there appeared to be no change to tank mass.. I assumed the same for others. (That they all had the stock dry mass for some reason :-) ).

LF/LOX combo more than triples the tank's dry mass with the Jumbo orange tank. LF/LOX uses a tank dry mass of 2.934. LF/OX uses a tank dry mass of 0.959.

I'm sure the values would come out as expected when this is taken into account, I'll give that a try.

Edit:

It was indeed tank dry mass. You guys are onto something here with the tank masses being off.

Edited by s20dan
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s20dan

s20dan

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I don't think this was mentioned, but there appears to be a bug in the RealTankTypes.cfg that basically means that Oxidiser and Liquid Fuel tanks weigh nothing!

Code tags don't seem to work?

@TANK[LiquidFuel]

{

@utilization = 1.0

@mass = 0.0005

@amount = full

@maxAmount = 40%

This is from the Default tank section' date=' but every tank has a similar section. Take note of [b']@mass = 0.0005. It's using the @ sign but that line does not exist, the @ sign should be removed.

If I'm correct the @ sign is used to replace a line, if that line does not exist it is not added/changed. Therefor Liqud Fuel tanks and Oxidiser tanks have no extra mass.. IE a tank section weighs the same with no internal tanks as it does with a liquid fuel or oxidiser or both tanks.

Remove the @ sign and those tanks will have a larger base mass (Perhaps too high), but will fall in-line with LOX tanks.

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AngelLestat

AngelLestat

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I still think that even removing the extra dry mass when we use h2 or h2+lox we will not get any extra benefic than use fuel+oxid. And that's without considering the extra drag that we will get from a big tank in real circustances.

I guess when we set our engines with h2+lox our engines isp needs to be a little higher than the ones already set it.

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Chestburster

Chestburster

Posted
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Unzip ModularFuelTanks.zip into {KSP}/GameData. You should have:

{KSP}/GameData/ModuleManager.dll

{KSP}/GameData/ModularFuelTanks/***_ModularFuelTanks.cfg

{KSP}/GameData/ModularFuelTanks/Plugins/ModularFuelTanks.dll

{KSP}/GameData/ModularFuelTanks/Resources/TankTypes.cfg

{KSP}/GameData/ModularFuelTanks/RealFuels.zip

Then, if you want to play with LOX and LH2 and all the goodies, unzip RealFuels.zip - otherwise leave it zipped to stick with LiquidFuel and Oxidizer.

Hope this helps. Typing from my smartphone sucks -.-

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Starwaster

Starwaster

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Posted (edited)
I'll test that later today, but who calculates you the ÃŽâ€V? As I already said I'm pretty confident that the calculations KSP is doing are correct.

Fabian

Only in a vacuum are they correct so make sure that your final orbital payload is the only one being tested. (for the nuclear testing I assume that is the case...)

The LF/OX actually has less fuel mass than the LF/LOX rocket as it's carrying some dead weight (it was easier to get the desired mass that way) and it still comes out on top.

(Oh I realise that's a mod tank, the result is the same with the Jumbo orange tank).

LOX is lighter and counts less towards thrust than the chemical oxidizer, therefore more of it has to be burned per second to attain the thrust rating specified. When I first started playing I thought some propellants were too heavy so I tried decreasing their resource densities and found that they got burned through even faster. I think that's been discussed previously elsewhere....

I don't think this was mentioned, but there appears to be a bug in the RealTankTypes.cfg that basically means that Oxidiser and Liquid Fuel tanks weigh nothing!

Code tags don't seem to work?

This is from the Default tank section, but every tank has a similar section. Take note of @mass = 0.0005. It's using the @ sign but that line does not exist, the @ sign should be removed.

If I'm correct the @ sign is used to replace a line, if that line does not exist it is not added/changed. Therefor Liqud Fuel tanks and Oxidiser tanks have no extra mass.. IE a tank section weighs the same with no internal tanks as it does with a liquid fuel or oxidiser or both tanks.

Remove the @ sign and those tanks will have a larger base mass (Perhaps too high), but will fall in-line with LOX tanks.

Also, I suggest the following for the nuclear engine. This won't affect any of its performance issues being discussed currently but is more canonically correct for ModuleManager: (replaces everything up to the line that starts with @atmosphereCurve)

And code tags have to be in caps (CODE)


    @maxTemp = 2200
    @MODULE[ModuleEngines]
    {
    @maxThrust = 333.6
    @heatProduction = 300

    !PROPELLANT[LiquidFuel]
    !PROPELLANT[Oxidizer]

    PROPELLANT
    {
        name = LiquidH2
        ratio = 0.99999999999
    }
    PROPELLANT
    {
        name = nuclearFuel
        ratio = 0.00000000001
    }

Finally, some thoughts on the LV-N issue. I've been researching everything I can on NERVA but it's a bit hard because some of the specs I've found on NERVA rockets were for proposed future versions. So I tried to focus on the actual engines that were tested and versions of which would have ended up on Saturn rockets until the project was defunded. The following pages I'm finding most interesting. So far discussion is focusing on things like fuel tank mass and fuel-tank mass ratios, but none of that really affects anything but your final TWR

So I was curious as to just how the fuel consumption of the LVN (especially the modified one in this mod) actually would stack up against real life counterparts. It's hard to find information about that because there's so MUCH of it available and for things like wiki entries I'd LIKE to be able to trace down sources so it's taking me a while

There is wiki page that lists specs for a NERVA-2 engine very close to what we have in KSP except that it had a thrust rating of 333.6 kN. Information is provided not just for the engine but for the entire Saturn third stage it would have driven. I had to make some assumptions on how much of the consumables were H2. For simplicity's sake I went with 100%. The result is that it consumes 120kg of H2 per second.

I changed the thrust for the LVN (for this mod) to match and it burns through 1,831 kg of H2 in 1 min, 23 sec. That's about 22 kg/s so it's consuming quite a bit less. The stock/modded version with 60 kN of thrust (the equivalent of NERVA1) consumes about 5x less. Quite a big discrepancy but it's a discrepancy in our favor since it means the engine is much more fuel efficient than we're giving it credit for. We're just not carrying enough H2 around. Given how light it is we can carry quite a lot of it. My test ship had 6 drop tanks that it jettisons in pairs as they empty. (using fuel hoses to route fuel as appropriate)

I do question though whether or not H2 should maybe be made denser, but then we start getting into volumes, so how much do we actually know about fuel tank volumes? I've seen the term 'kerbos' bandied about as a hypothetical unit of volume as opposed to just using liters, kL or m3. But I never really understood why that was. Is it because we don't really know what these tank volumes represent? Or are there other reasons?

Edit: Linking to referenced pages

http://en.wikipedia.org/wiki/NERVA

Another interesting page; this one talks about the engines that were part of the von Braun Mars proposal. In performance they seem close to NERVA1 and KSP's LVN and list a fuel consumption rate of 8.5 kg/s

http://www.astronautix.com/engines/neralpha.htm

Edited by Starwaster
Linking to some reference pages
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s20dan

s20dan

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Posted

I do question though whether or not H2 should maybe be made denser, but then we start getting into volumes, so how much do we actually know about fuel tank volumes? I've seen the term 'kerbos' bandied about as a hypothetical unit of volume as opposed to just using liters, kL or m3. But I never really understood why that was. Is it because we don't really know what these tank volumes represent? Or are there other reasons?

The thing is a lot of engines use LH2, making it more dense would likely make LOX/LH2 rockets far too effective.

I've been playing with tank dry masses and a slight tinkering of ISPs, I have a setup that seems to work for LF/OX, LF/LOX and for LOX/LH2, but still not for LH2 + NERVA.

LOX tanks use mass = 0.0003

LF and OX tanks both use mass = 0.00025

WRT Volume it seems that values were just picked that worked and each tank is scaled accordingly, but I guess volume (m^3) could be calculated using a fuel's density and the mass of the fuel contained in the tank and checked with the physical dimensions of the tank.

I think CaptainArbitrary said he had done something like that.

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RuBisCO

RuBisCO

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Posted
I am sorry if someone already asked this (I dont want to read 41 pages of forum), but I am trying to install this and it wont work, can someone please give me some step by step instructions to install this mod, thanks.

I and other had the same problem, generally it was found that in the Zip there are 2 files as "Gamedata" and a file for Apple OS call MACOSX, do NOT extract the latter unless your running kerbal space on an apple computer. Just copy the Gamedata from the zip, paste it into your KSP folder, overwriting the previous gamedata, then in the your KSP gamedata folder you will find the "ModularTankFuel" folder, open that and inside extract the fold called "RealFeuls".

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Starwaster

Starwaster

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Posted
The thing is a lot of engines use LH2, making it more dense would likely make LOX/LH2 rockets far too effective.

I've been playing with tank dry masses and a slight tinkering of ISPs, I have a setup that seems to work for LF/OX, LF/LOX and for LOX/LH2, but still not for LH2 + NERVA.

LOX tanks use mass = 0.0003

LF and OX tanks both use mass = 0.00025

WRT Volume it seems that values were just picked that worked and each tank is scaled accordingly, but I guess volume (m^3) could be calculated using a fuel's density and the mass of the fuel contained in the tank and checked with the physical dimensions of the tank.

I think CaptainArbitrary said he had done something like that.

Unless tanks are grossly overweight then it's probably not that big a deal. Look at how massive some of the Saturn stages were. I haven't seen anything in that neighborhood yet but then the largest tanks I've used were 3.75 (from the KW Rocketry pack)

Rocket tanks are really massive. And I'm leaning back towards something I said in my earlier post which is that we just need to get used to carry massive amounts of H2.

I mean really, NERVA has to be considered our entry-level nuclear rocket... that's all it ever was IRL with better rockets down the pipeline. Or research different nukes using different propellants like ammonia. I have no idea what the performance characteristics of that would be though.... Probably some information about it to be found at ProjectRho...

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somnambulist

somnambulist

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Posted
I and other had the same problem, generally it was found that in the Zip there are 2 files as "Gamedata" and a file for Apple OS call MACOSX, do NOT extract the latter unless your running kerbal space on an apple computer. Just copy the Gamedata from the zip, paste it into your KSP folder, overwriting the previous gamedata, then in the your KSP gamedata folder you will find the "ModularTankFuel" folder, open that and inside extract the fold called "RealFeuls".

Actually _MACOSX won't even show up under OS X. It's just OS X's way of handling extended file attributes on non-HFS+ file systems like Fat32 or NTFS, but gets transparently merged back into the files when unzipped on OS X. (Technically it could be stripped out of the Zip archive entirely, along with the entire .Git folder hierarchy. )

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Titan Space Agency

Titan Space Agency

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I and other had the same problem, generally it was found that in the Zip there are 2 files as "Gamedata" and a file for Apple OS call MACOSX, do NOT extract the latter unless your running kerbal space on an apple computer. Just copy the Gamedata from the zip, paste it into your KSP folder, overwriting the previous gamedata, then in the your KSP gamedata folder you will find the "ModularTankFuel" folder, open that and inside extract the fold called "RealFeuls".

Can someone give me more in depth instructions i did this but it still wont run. I am using a windows XP.
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p1t1o

p1t1o

Posted
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After you install, look inside your gamedata folder.

If you have installed it correctly (for windows), you should have:

A folder called ModularFuelTanks, which contains a RealFuels.ZIP file and the following folders:

.git

Resources

Plugins

If you want to install RealFuels, look inside RealFuels.ZIP and pull the folder out of there and into your ModularFuelTanks folder.

Your ModularFuelTanks folder now contains a fourth folder, called RealFuels. Advanced fuels are now active.

Chestburster has written some extra .cfg files for some of the more popular mods that contain fuel tanks or engines, here.

If you want to use them (for example, this mod will have no effect on the tanks and engines from KW rocketry without Chestbursters configs), unzip the entire contents of his archive into your ModularFuelTanks directory.

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JeBuSBrian

JeBuSBrian

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Posted
It is still not working for me ;.; Where deos the Game data folder that is in the modular fuels mod go, i need to know exactly where everything needs to go ;.;

Seriously?

The GameData folder that comes with any mod will drop into the same place as the GameData folder that exists with the vanilla game. Drop it straight into the root KSP directory.

This is not rocket surgery.

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AngelLestat

AngelLestat

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Posted
Finally, some thoughts on the LV-N issue. I've been researching everything I can on NERVA but it's a bit hard because some of the specs I've found on NERVA rockets were for proposed future versions. So I tried to focus on the actual engines that were tested and versions of which would have ended up on Saturn rockets until the project was defunded. The following pages I'm finding most interesting. So far discussion is focusing on things like fuel tank mass and fuel-tank mass ratios, but none of that really affects anything but your final TWR

So I was curious as to just how the fuel consumption of the LVN (especially the modified one in this mod) actually would stack up against real life counterparts. It's hard to find information about that because there's so MUCH of it available and for things like wiki entries I'd LIKE to be able to trace down sources so it's taking me a while

There is wiki page that lists specs for a NERVA-2 engine very close to what we have in KSP except that it had a thrust rating of 333.6 kN. Information is provided not just for the engine but for the entire Saturn third stage it would have driven. I had to make some assumptions on how much of the consumables were H2. For simplicity's sake I went with 100%. The result is that it consumes 120kg of H2 per second.

I changed the thrust for the LVN (for this mod) to match and it burns through 1,831 kg of H2 in 1 min, 23 sec. That's about 22 kg/s so it's consuming quite a bit less. The stock/modded version with 60 kN of thrust (the equivalent of NERVA1) consumes about 5x less. Quite a big discrepancy but it's a discrepancy in our favor since it means the engine is much more fuel efficient than we're giving it credit for. We're just not carrying enough H2 around. Given how light it is we can carry quite a lot of it. My test ship had 6 drop tanks that it jettisons in pairs as they empty. (using fuel hoses to route fuel as appropriate)

I do question though whether or not H2 should maybe be made denser, but then we start getting into volumes, so how much do we actually know about fuel tank volumes? I've seen the term 'kerbos' bandied about as a hypothetical unit of volume as opposed to just using liters, kL or m3. But I never really understood why that was. Is it because we don't really know what these tank volumes represent? Or are there other reasons?

The isp of nerva engines can reach 1000 with ease, and if we use better materials so the core can reach higher temperatures then the isp increase even more.

All those values that you mention are from the 60s.

The best way to make a nerva engine is with radiators to release the heat using a brayton cycle so we not need to shutdown the core, and we will generate electricity when we dont needed to thrust.

The good about nerva engines is that only needs H2, this is the half of the fuel that chemicals rockets needs and we can get this from water, using the core to separate h2 from water and we have fuel again. So any asteroid or little planet (duna) with water it would serve to supply.

http://www.gizmag.com/nasa-nuclear-cryogenic-propulsion/25772/

http://www.penny4nasa.org/tag/nerva/

http://www.aerospaceamerica.org/Documents/Augustine%20Commission%20Reports/Rover_NERVA.pdf

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JeBuSBrian

JeBuSBrian

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Posted
Every time i try that though it ask me to merge the folders and i wont let me not merge them and put it in the main derectory. thats why i am having truble.:mad:
...

Look, I don't want to sound like an ass, but how long have you been using a computer? Because, well... this is a pretty simple concept. If you want files in Folder A to be in Folder B, you need to merge them. Yes, merge the folders.

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Titan Space Agency

Titan Space Agency

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Posted
Look, I don't want to sound like an ass, but how long have you been using a computer? Because, well... this is a pretty simple concept. If you want files in Folder A to be in Folder B, you need to merge them. Yes, merge the folders.
And i dont want to sound like a dumy that has truble instaling things proporly!
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