Nertea

[1.7.x] Kerbal Atomics: fancy nuclear engines! (Sept 11)

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1 hour ago, blowfish said:

What are you using to compare?  If you're using the same size tank, I'm not surprised, because oxidizer is very dense compared to LH2.  I'd recommend trying to hold total vessel mass constant.

...Yeah you're absolutely right. I was looking at the whole situation in term of volume and not mass. After more tinkering about I'm starting to see that NTR vessels can get... quite huge.

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since NTR`s can use any propelant, can you add the option to use any and all forms of fuel in the game?(but evry fuel whit diffrent ISP)

xenon, LF, LH2 and maybe even ox (but perhaps whit som chance of killing the NTR) 

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On 7/30/2016 at 3:15 AM, danielboro said:

since NTR`s can use any propelant, can you add the option to use any and all forms of fuel in the game?(but evry fuel whit diffrent ISP)

xenon, LF, LH2 and maybe even ox (but perhaps whit som chance of killing the NTR) 

Not really true. You could design an NTR to use just about any fuel you wanted to, but you couldn't (for example) take an NTR that was designed to use LH2 and suddenly run water through it. The design process would have to take into consideration how the neutron moderation characteristics of the coolant would affect reactivity in the core. You could have the NTRs in the game do this, but you'd be taking a seriously long hike off of Reality Ranch. 

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I'm rather early in the tech tree in my current playthrough and I thought I'd give this mod a try. I wanted to design some rather large interplanetary probes with the ISP-advantage of a nuclear engine. However, with the early nuclear engines (stock NERV and two engines from Stock Extension) I had to build such preposterously large tugs for the probes to get more dV than with efficient stock LF/Ox engines on a vessel with the same weight that I ended up deleting the patch files for Squad and SXT. In my opinion these low-tech engines, with their relatively small ISP compared to the engines in this pack, are close to impractical with the LH patch. 

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@Flow There's definitely a delta-v threshold for which higher TWR chemical rockets are going to require smaller overall vessel mass.  The LH2 tanks do mass a bit more per ton of fuel than the LFO tanks, but not by that much.  They're big but they're not particularly heavy.  Nuclear engines are only going to make sense for very large delta-v requirements.

Edited by blowfish

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@Nertea you'd mentioned in January that you might come up with an option to let these engines burn LF instead of Hydrogen. Did you ever make that? I saw the LFO mod for your Cryogenics, but not for the nukes.

 

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15 hours ago, tjt said:

@Nertea you'd mentioned in January that you might come up with an option to let these engines burn LF instead of Hydrogen. Did you ever make that? I saw the LFO mod for your Cryogenics, but not for the nukes.

There's a MM config file in the Extras folder that switches the engines from using LH2 to LF. Just drag and drop it anywhere into your GameData folder and you'll be GTG. 

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Maybe an odd request. But is there a way I could tweak the liquid hydrogen properties in the community resource file to make all liquid hydrogen using engines more efficient? Or perhaps a simple mm module?

i ask because I've played a lot of kerbal and in my current game I'm just screwing around with crazy larger ships and bases which become prohibitively slow and heavy with fuel to get anywhere.  I'd like more of a casual play through this time. I don't want to make it too easy, but maybe 150% more efficient. Even just lowering the weight a bit would help.

 

i tried modifying density of liquid hydrogen and did get much more deltav in the same ship size, but the tanks weighed a huge amount.

Edited by skald

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16 hours ago, Overlocker96 said:

There's a new version of the Kerbalism mod that support radiation from parts, like NERVAs. I wonder if you are going to make a MM patch for this 4 engines.

Made one. Plugged some numbers into it that made sense to me. You can adjust them as they make sense to you. 

// ============================================================================
// Kerbal Atomics emitters
// ============================================================================

@PART[ntr-gc-25-1]:AFTER[KerbalAtomics]
{
  MODULE
  {
    name = Emitter
    radiation = 0.0000083333 // 0.03 rad/h
    tooltip = This engine emits ionizing radiation.
  }
}

@PART[ntr-sc-25-1]:AFTER[KerbalAtomics]
{
  MODULE
  {
    name = Emitter
    radiation = 0.0000055555 // 0.02 rad/h
    tooltip = This engine emits ionizing radiation.
  }
}

@PART[ntr-sc-125-1]:AFTER[KerbalAtomics]
{
  MODULE
  {
    name = Emitter
    radiation = 0.0000027777 // 0.01 rad/h
    tooltip = This engine emits ionizing radiation.
  }
}

@PART[ntr-sc-125-2]:AFTER[KerbalAtomics]
{
  MODULE
  {
    name = Emitter
    radiation = 0.0000027777 // 0.01 rad/h
    tooltip = This engine emits ionizing radiation.
  }
}

 

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I made a base with planetary base systems, but the ISRU there won't allow me to make LH2. I have it set up in the cfg file to, but it is saying that it is full, when I have a partially empty lh2 tank attached. How would i go about writing a MM config to change this if that is what I need to do or is there something I'm missing? The following is the addition I have made in the cfg file if anyone wants to take a look at that as well.

 

Thanks!

Quote

MODULE
    {
        name = ModuleResourceConverter
        ConverterName = LH2
        StartActionName = Start ISRU [LH2]
        StopActionName = Stop ISRU [LH2]
        AutoShutdown = true
        TemperatureModifier
        {
            key = 0 100000
            key = 750 50000
            key = 1000 10000
            key = 1250 500    
            key = 2000 50    
            key = 4000 0
        }                
        GeneratesHeat = true
        DefaultShutoffTemp = .8
        ThermalEfficiency 
        {
            key = 0 0 0 0
            key = 500 0.1 0 0
            key = 1000 1.0 0 0
            key = 1250 0.1 0 0
            key = 3000 0 0 0 
        }
        UseSpecialistBonus = true
        SpecialistEfficiencyFactor = 0.2
        SpecialistBonusBase = 0.05
        Specialty = Engineer
        EfficiencyBonus = 1

         
         INPUT_RESOURCE
         {
            ResourceName = Ore
            Ratio = 0.4
         }
         INPUT_RESOURCE
         {
            ResourceName = ElectricCharge
            Ratio = 24
         }
         OUTPUT_RESOURCE
         {
            ResourceName = LqdHydrogen
            Ratio = 0.8
            DumpExcess = false
         }
    }

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On 8/15/2016 at 0:00 PM, skald said:

Maybe an odd request. But is there a way I could tweak the liquid hydrogen properties in the community resource file to make all liquid hydrogen using engines more efficient? Or perhaps a simple mm module?

i ask because I've played a lot of kerbal and in my current game I'm just screwing around with crazy larger ships and bases which become prohibitively slow and heavy with fuel to get anywhere.  I'd like more of a casual play through this time. I don't want to make it too easy, but maybe 150% more efficient. Even just lowering the weight a bit would help.

 

i tried modifying density of liquid hydrogen and did get much more deltav in the same ship size, but the tanks weighed a huge amount.

Just increase the Isp by 50%, that should do what you want :). 

On 8/15/2016 at 2:39 AM, Overlocker96 said:

There's a new version of the Kerbalism mod that support radiation from parts, like NERVAs. I wonder if you are going to make a MM patch for this 4 engines.

I would leave it to Kerbalism to do that, as last I checked, Kerbalism messes around with a lot of balance-related things that I'm not comfortable supporting. Alternately, the one that @TheSaint made there seems good!

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I have a large ship using the insulating hydrogen tanks, and when I right click on them it says they are pulling electric charge, but according the the resource panel and KER I am still getting boil-off. I have alternate resource panel and also action groups extended (started happening after I shut my reactor off and then back on). I have enough electric charge, as that is not dropping. I'm not sure what it could be as my last craft using LH2 tanks worked, so I'll try uninstalling Alternate resource panel and action groups extended since I didn't have those last time.

Edit: Uninstalling those doesn't seem to help either. I think the problem came since I have the LH2 tanks tied to action groups, I accidentally pressed the wrong button and quickly pressed it again to revert to cooling. I'll try to dig into the persistant file and see what I can find there.

Edit 2: It seems it has something to do in the save file. When I disabled cooling it changed it in the save file, but when I re-enabled cooling it didn't change it back. 

Edited by HoveringKiller
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On 8/23/2016 at 1:09 AM, HoveringKiller said:

I have a large ship using the insulating hydrogen tanks, and when I right click on them it says they are pulling electric charge, but according the the resource panel and KER I am still getting boil-off. I have alternate resource panel and also action groups extended (started happening after I shut my reactor off and then back on). I have enough electric charge, as that is not dropping. I'm not sure what it could be as my last craft using LH2 tanks worked, so I'll try uninstalling Alternate resource panel and action groups extended since I didn't have those last time.

Edit: Uninstalling those doesn't seem to help either. I think the problem came since I have the LH2 tanks tied to action groups, I accidentally pressed the wrong button and quickly pressed it again to revert to cooling. I'll try to dig into the persistant file and see what I can find there.

Edit 2: It seems it has something to do in the save file. When I disabled cooling it changed it in the save file, but when I re-enabled cooling it didn't change it back. 

It's a known bug. If for any reason the tanks start boiling off (out of power, turn off cooling), they'll never stop boiling off, despite what the GUI says.  You can edit your persistent.sfs file to remove the "boiloff = true" to fix it.

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5 hours ago, hab136 said:

It's a known bug. If for any reason the tanks start boiling off (out of power, turn off cooling), they'll never stop boiling off, despite what the GUI says.  You can edit your persistent.sfs file to remove the "boiloff = true" to fix it.

That's what I did haha. I've never had it happen before this time. Thanks!

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@Nertea and others, I've been tinkering with SSTOs of the vertical lift variety and been having a lot of fun using the Kerbal Atomics engines; in particular the high ISP Liberator. However, I have one last challenge I'm trying to tackle, and that's getting one that works decently in non-oxygen atmospheres. For now I just make huge ships with many Liberators, but that only goes so far, and it's inelegant. There's several atmosphere breathing fission ramjets I've seen, using simply a reactor and the ATM resource, but they're heavy and low thrust. While I'm not trying to be terribly scientifically accurate, it stands to reason you could have something like an atmosphere-augmented version of the Kerbal Atomics engines, that in atmosphere they would burn LqdHydrogen and IntakeAtm for additional thrust like a ramjet. Or, perhaps using a combination of LqdHydrogen, Oxidizer and IntakeAtm. The goal for me, is nuclear landers/rockets/spaceplanes that can comfortably operate in non-oxygen atmospheres.

So, to this end I started tinkering with making duplicate versions of these engines and tweaking them to use IntakeAtm as a fuel. I've got them (and a variant of the Mark IV Broadsword as well) in a useful state, but now I wanted to try and make these at least somewhat balanced. Right now I'm trying to keep ISP, thrust and weight similar to the parent engines, with tweaks towards heavier, lower thrust, and little lower ISP in closed cycle mode. In air-breathing mode, ISP is still similar to a jet (in the 2000-3000 range). I've noticed @Nertea seems to be using some method to the madness of stats like ISP, thrust, weight, cost, etc. Any thoughts on how I could try and balance engines like this to fit in? 

Would this be something you might want to fold into to the Kerbal Atomics mod itself? Being a fan of standards, I'd love for this concept to be pulled into this mod, but I know it's a lot of work, so I'll be happy with something that at least feels standard on my own computer, too. I'd gladly post the changes I made to the files if it helps.

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On 8/27/2016 at 8:29 AM, AmpCat said:

@Nertea and others, I've been tinkering with SSTOs of the vertical lift variety and been having a lot of fun using the Kerbal Atomics engines; in particular the high ISP Liberator. However, I have one last challenge I'm trying to tackle, and that's getting one that works decently in non-oxygen atmospheres. For now I just make huge ships with many Liberators, but that only goes so far, and it's inelegant. There's several atmosphere breathing fission ramjets I've seen, using simply a reactor and the ATM resource, but they're heavy and low thrust. While I'm not trying to be terribly scientifically accurate, it stands to reason you could have something like an atmosphere-augmented version of the Kerbal Atomics engines, that in atmosphere they would burn LqdHydrogen and IntakeAtm for additional thrust like a ramjet. Or, perhaps using a combination of LqdHydrogen, Oxidizer and IntakeAtm. The goal for me, is nuclear landers/rockets/spaceplanes that can comfortably operate in non-oxygen atmospheres.

So, to this end I started tinkering with making duplicate versions of these engines and tweaking them to use IntakeAtm as a fuel. I've got them (and a variant of the Mark IV Broadsword as well) in a useful state, but now I wanted to try and make these at least somewhat balanced. Right now I'm trying to keep ISP, thrust and weight similar to the parent engines, with tweaks towards heavier, lower thrust, and little lower ISP in closed cycle mode. In air-breathing mode, ISP is still similar to a jet (in the 2000-3000 range). I've noticed @Nertea seems to be using some method to the madness of stats like ISP, thrust, weight, cost, etc. Any thoughts on how I could try and balance engines like this to fit in? 

Would this be something you might want to fold into to the Kerbal Atomics mod itself? Being a fan of standards, I'd love for this concept to be pulled into this mod, but I know it's a lot of work, so I'll be happy with something that at least feels standard on my own computer, too. I'd gladly post the changes I made to the files if it helps.

I'd be kidding if I said the jet engine stats from Mark IV were balanced by any kind of logic :P, so I can't speak to atmosphere beyond "play around with numbers". KA is mostly balanced as follows: take RL engine, add 10% Isp if LH2, match TWR to "tech level" of the engine, where LV-N = 0, determine approximate desired thrust (based off diameter, mostly) and work back from that to get mass. There isn't a huge amount of math or equations involved there, so I'd just start with something you like and reduce if too easy, increase if too hard.

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I had guessed a lot of this is 'what feels right', but looking at the conversion of nuclear engines from other sources to use LH2 instead of LF, you did have some reasoning behind the numbers, since they were consistent and seemed rather specific.

I guess what I'm really after is a nuclear Broadsword, running either LF or LH2 and Atm in air-breathing and just LF/LH2 in closed cycle. And closer in diameter to 3.75m or Mk3 parts. I just love the looks of the models from Kerbal Atomics! But then again, I like the low-profile of the Broadsword. I just hate throwing off huge chunks of rocket for my missions. Feels.. wasteful. Inelegant.

Well, if you ever need ideas for a new class of part, I'd love some Atm-breathing, LH2 (or LF)  burning, multi-mode atomic engines! Basically, a nuclear-assisted internal aerospike engine. I'd love to help where I can. While I've done modeling before, used Unity, and am a software guy by profession, I confess I've never tried to mod before. Maybe I can take this as an opportunity to get back into modeling after all these years and make a spin-off atomic engines mod. I won't delude myself into thinking I can make comparable models, however.

P.S. How come no one else uses turbo-ramjet assisted vertical launch rockets? I can easily get one to 80 or even 100km apoapsis before the engine runs out of air at 25-30km altitude, then use rockets to circularize. Just have to be careful not to overheat my nosecone and those LH2 tanks. I've even got mine landing vertically again from orbit onto Kerbin.

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@Nertea, this actually brings up another question: Is it possible in KSP to have say a LH2 + Atm engine running at something like 2000 ISP, then as the Atm lowers, just that portion of the ISP drops off? So when you get to vacuum, rather than switching modes, you're just running at LH2 ISPs. I'm imagining if I have propellant ratios at 1 and 1, and ISP to 2000, as the Atm pressure lowers, will ISP slowly drop down to 1000. Can I set the flameout percentage to 0% or something, and it just run fine without Atm and only the LH2? No idea if the game allows this or if you have to switch to another mode.

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21 hours ago, AmpCat said:

@Nertea, this actually brings up another question: Is it possible in KSP to have say a LH2 + Atm engine running at something like 2000 ISP, then as the Atm lowers, just that portion of the ISP drops off? So when you get to vacuum, rather than switching modes, you're just running at LH2 ISPs. I'm imagining if I have propellant ratios at 1 and 1, and ISP to 2000, as the Atm pressure lowers, will ISP slowly drop down to 1000. Can I set the flameout percentage to 0% or something, and it just run fine without Atm and only the LH2? No idea if the game allows this or if you have to switch to another mode.

I think you would have to change engines. Even if the flameout percentage is zero, the engine will still run out of "fuel" (IntakeAir) if it isn't present. As far as I know, the flameout percentage is there purely to keep flameouts symmetric. 

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Minor update:

  • Balance tweaks to NTRs
  • Added some model features and patches for Radioactivity dev
  • Fixed an issue with cryogenic boiloff never turning off if cooling failed

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1 minute ago, Nertea said:

Minor update:

  • Balance tweaks to NTRs
  • Added some model features and patches for Radioactivity dev
  • Fixed an issue with cryogenic boiloff never turning off if cooling failed

You are the best! I have all of your mods and consider them essential. I have yet to be able to donate to your coffee fund but I start a new part time job next week, and it is high on my list of things to do. Keep up the great work!

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Nice! I should throw something into the coffee fund myself. All my stuff heavily uses Near Future Tech. Mostly because I'm a snob about good looking models, and Nertea does an exceptional job with model quality.

Also, if we wanted to suggest more of the NTRs and other associated parts are supported in TweakScale, who handles that? Nertea, or TweakScale's owner? Looks like it's easy enough to patch myself, but figured I should point out to the appropriate authority that several parts seem to be missing. If they're explicitly left out for ReasonsTM, that's fine too, just want to know.

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19 hours ago, AmpCat said:

Nice! I should throw something into the coffee fund myself. All my stuff heavily uses Near Future Tech. Mostly because I'm a snob about good looking models, and Nertea does an exceptional job with model quality.

Also, if we wanted to suggest more of the NTRs and other associated parts are supported in TweakScale, who handles that? Nertea, or TweakScale's owner? Looks like it's easy enough to patch myself, but figured I should point out to the appropriate authority that several parts seem to be missing. If they're explicitly left out for ReasonsTM, that's fine too, just want to know.

Talk to TweakScale people. I don't really... like... tweakscale but support is easy enough for them/you to add, I think. 

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I kind of figured, judging from the unique stats and models for various engine sizes.

Maybe we can convince you at some point to add 3.75m engines! (after Atm breathing ones, of course!) :lol: You know, with all that free time you have.

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