[1.8+] Real Fuels

[Starwaster]

*FACEPALM SELF*

I have NO idea how the heck I even did that....

[NathanKell]

No problem, it's fixed on the CKAN side so no matter what it'll work in future. You still get massive kudos for an awesome release, worry not.

[westamastaflash]

Starwaster apparently packed the zip different from how we normally do, and CKAN didn't know what to do with it. The CKAN folks kindly updated our metadata to work with either directory structure, so it should be appearing shortly.

Thanks much! Excellent job with the update by the way.

[lextacy]

Hi, new to this mod.

1. Can someone explain the gameplay element in this mod? I mean I know you can use real life fuels. That is just the aesthetics part of it I think. Are we choosing what fuel to run in the engine just because?, or is there a deeper purpose such as "this fuel will suck on this engine , but will run great on that engine". So lets say I choose to run LiqHyd+LOX on a LV-30. What is to stop me from just choosing any fuel from the list and be just as better off? I know limited ignitions&ullage add a little to the true gameplay of the mod. Beyond that Im hoping this mod will offer a dynamic gameplay in the fuel mixture aspect of it.

2. I want to make an alcohol fuel like was used on the V2. Is it possible to make your own fuels up in this mod?

[NathanKell]

1 sounds more like a question for the RF Stockalike thread. RF doesn't actually include engine configs, just everything else. In real life, however, engines pretty much can only run on one mixture (though the mixture ratio can vary). In some few cases you can get away with substituting one fuel for another, or one oxidizer for another.

2. The V-2 used 75% Ethanol / 25% water as the fuel. That is the propellant Ethanol75, which RealFuels has had since...well, about since it started.

[regex]

2. I want to make an alcohol fuel like was used on the V2. Is it possible to make your own fuels up in this mod?

You'll find that pretty much every fuel seriously considered as viable IRL was included in Real Fuels and then later in the Community Resource Pack. There may be a few missing but they were either too obscure or merely "on-paper" proposals. Any rocket that actually flew IRL will have its fuel represented.

[lextacy]

thanks Nathan and regex. Those answers were great ! I dont need to make new fuel then and focus on more evil things...................like making smoke plumes insanely thick and huge at launch !

[ebigunso]

thanks Nathan and regex. Those answers were great ! I dont need to make new fuel then and focus on more evil things...................like making smoke plumes insanely thick and huge at launch !

Try picking up RealPlume, probably that should do exactly that and more. Don't forget it's dependency SmokeScreen too.

[Starwaster]

Updated Heat Pump to version 1.1 (increases compatibility for Real Fuels version 10.7.0)

https://github.com/Starwaster/HeatPump/releases/latest

[lextacy]

I cant change thrust or ISP levels after installing Real Fuels. Is there some sort of "block" that real fuels imposes on the player? Im using module manager.

[NathanKell]

Did you install an engine pack?

[lextacy]

Did you install an engine pack?

I have the soviet pack with RF built in configs for it. I have FASA pack also with a community RF config. What I found out is I can change the values successfully if I use part copy ($PART) and make a new part out of it. However I dont want a mess of duplicate engines everywhere.

[NathanKell]

lextacy: The OP states the RF does not come with any engine configs. It directs you to the second post, which has links.

[Jovus]

I seem to have run into an issue with adding hydrazine to procedural tanks. It works...sometimes. Specifically, only occasionally when I attach RCS thrusters or the generic 1kN orbital maneuvering engine (I'm also using RO and RSS) will I be given the option to add a tank of hydrazine. In any case, when I open the tank GUI, Hydrazine is not among the fuels listed as an option.

Have any of you heard of this or a similar issue before? I've uninstalled and reinstalled RF to no avail, and sadly there are no relevant logs to share.

[Nerd1000]

How does RF calculate boiloff rate? All the LH2 in my FASA Apollo CSM disappears within hours of launch, leaving the ship without electrical power- seeing as this didn't happen IRL, either the RO configs for the parts are messed up or something odd is going on with the boiloff rate calculation.

[NathanKell]

Jovus: You need a highly pressurized tank. ServiceModule or Fuselage type. Switch type to one of them.

[Starwaster]

How does RF calculate boiloff rate? All the LH2 in my FASA Apollo CSM disappears within hours of launch, leaving the ship without electrical power- seeing as this didn't happen IRL, either the RO configs for the parts are messed up or something odd is going on with the boiloff rate calculation.

I'll look into it. I'm assuming that the fuel tank type is ServiceModule, right? (it better be!)

Assuming that it was a ServiceModule (which I bumped up the insulation on) then there's one of two possibilities that I can see:

1. I didn't give the H2 tank enough insulation and it needs to be increased.
   
2. There's a bug that is apparently triggered by the stock radiators that can cause all of the coldest propellant in a given tank to immediately be deleted. I just had this one reported to me today. I think I know what the cause is as I had to address something like this before release but apparently it can still happen. So I'll push another update for 1.0.4 soon.
   

[Jovus]

Thanks NathanKell, that was exactly the problem I was running into. Now I know!

Complete non-sequiter: I was poking around, and ran into a paper on a demonstration of a system for long-term hydrogen storage with zero boiloff for space applications, and thought you guys might be interested, because it's interesting. http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20110004377.pdf

[Nerd1000]

I'll look into it. I'm assuming that the fuel tank type is ServiceModule, right? (it better be!)

Assuming that it was a ServiceModule (which I bumped up the insulation on) then there's one of two possibilities that I can see:

1. I didn't give the H2 tank enough insulation and it needs to be increased.
   
2. There's a bug that is apparently triggered by the stock radiators that can cause all of the coldest propellant in a given tank to immediately be deleted. I just had this one reported to me today. I think I know what the cause is as I had to address something like this before release but apparently it can still happen. So I'll push another update for 1.0.4 soon.
   

Yeah, its a Service module type tank. There seems to be a constant drain well above the rate you'd expect, which causes all the fuel to be gone around 9 hrs into the flight. I added another 480L of LH2 in side tanks, which bought me another 9hrs or so (original capacity is 410L). I've not got any radiators on the pod.

I had a look at my realtanktypes cfg file- the service module has the same insulation thickness as the Cryogenic tank and also the default tank (!). The insulation conductivity however is much lower and the tank wall is set to be thinner (0.001 rather than 0.0025 for the other two). Maybe I've got a old or messed up config?

Edited November 5, 2015 by Nerd1000

[Laie]

ran into a paper on a demonstration of a system for long-term hydrogen storage

Whoa! I was wondering if standard refrigeration would work down to 20K, and if so, then how. I didn't find this or anything else to answer the question, so thanks for bringing it up.

Side node: "we used a (brand) (model) cryocooler" -- I certainly didn't expect that such a device could be bought off the shelf.

[billkerbinsky]

Side node: "we used a (brand) (model) cryocooler" -- I certainly didn't expect that such a device could be bought off the shelf.

Besides rocket fuel, cryogenics is used for a bunch of other fields. Lots of low temperature physics research out there; on the more practical side, every single hospital NMRMRI machine has a bunch of liquid helium keeping a very powerful superconducting electromagnet happy. With a little digging you can learn of some very kerbal-ish accidents involving those magnets...

[Starwaster]

Whoa! I was wondering if standard refrigeration would work down to 20K, and if so, then how. I didn't find this or anything else to answer the question, so thanks for bringing it up.

Side node: "we used a (brand) (model) cryocooler" -- I certainly didn't expect that such a device could be bought off the shelf.

Besides refrigeration (of the tank itself) you can also cool down any external insulation, so you're basically intercepting the heat before it can get inside the tank.

- - - Updated - - -

Yeah, its a Service module type tank. There seems to be a constant drain well above the rate you'd expect, which causes all the fuel to be gone around 9 hrs into the flight. I added another 480L of LH2 in side tanks, which bought me another 9hrs or so (original capacity is 410L). I've not got any radiators on the pod.

I had a look at my realtanktypes cfg file- the service module has the same insulation thickness as the Cryogenic tank and also the default tank (!). The insulation conductivity however is much lower and the tank wall is set to be thinner (0.001 rather than 0.0025 for the other two). Maybe I've got a old or messed up config?

Did you leave out a zero? Should be 0.0001 (which is probably still too high. I'm working on a new set of values)

Edited November 5, 2015 by Starwaster

[Nerd1000]

Besides refrigeration (of the tank itself) you can also cool down any external insulation, so you're basically intercepting the heat before it can get inside the tank.

- - - Updated - - -

Did you leave out a zero? Should be 0.0001 (which is probably still too high. I'm working on a new set of values)

Whoops, It is 0.0001. must have missed that zero.

I've done a little more experimentation, and I think I've found the root problem. The issue is that conduction rates into the LH2 tank are quite high, it's basically trying to cool the entire service module down to 20K. You probably wouldn't notice with a propellant tank due to the everything already being really cold, but the service module is only carrying a few tens of kilos of LH2 to run the fuel cells- the rest of contents are relatively warm storable stuff. When I tried removing the LH2 storage inside the SM and relying on the servicemodule type external tanks, the boiloff rate went from 0.01L/s to 0.17L/s because the starting temperature of the SM was higher. Replacing those servicemodule type tanks with a procedural cryo tank took boiloff rate to less than 0.01L/s (is there any way of making the resource list show more decimal places? It was displaying 0.00), but not low enough to prevent all the LH2 boiling off within 2 days.

I think I need more effective insulation for this application. For one boiloff is just too fast and secondly if freezing was modeled my storable fuel and oxidizer would be toxic snow. From what I've read the Apollo SM LH2 tanks were special items with extremely good insulation, so maybe another tank definition explicitly for this sort of role might be a solution.

Edited November 5, 2015 by Nerd1000
fixed a grammatical error

[Starwaster]

Whoops, It is 0.0001. must have missed that zero.

I've done a little more experimentation, and I think I've found the root problem. The issue is that conduction rates into the LH2 tank are quite high, it's basically trying to cool the entire service module down to 20K. You probably wouldn't notice with a propellant tank due to the everything already being really cold, but the service module is only carrying a few tens of kilos of LH2 to run the fuel cells- the rest of contents are relatively warm storable stuff. When I tried removing the LH2 storage inside the SM and relying on the servicemodule type external tanks, the boiloff rate went from 0.01L/s to 0.17L/s because the starting temperature of the SM was higher. Replacing those servicemodule type tanks with a procedural cryo tank took boiloff rate to less than 0.01L/s (is there any way of making the resource list show more decimal places? It was displaying 0.00), but not low enough to prevent all the LH2 boiling off within 2 days.

I think I need more effective insulation for this application. For one boiloff is just too fast and secondly if freezing was modeled my storable fuel and oxidizer would be toxic snow. From what I've read the Apollo SM LH2 tanks were special items with extremely good insulation, so maybe another tank definition explicitly for this sort of role might be a solution.

About making the resource list more accurate: not that I know of, not for the stock list. (when testing this, if I need more accuracy then I put in custom debug messages into the part action menu. Speaking of which, did you see the private message I sent you?)

I don't think we need another tank type, just improve the insulation on the ServiceModule type. (hmmm just thought of something. Has it been POSITIVELY verified that the tank you were using before is actually using ServiceModule instead of Default? Need to look at the part config and double check that....)

[Nerd1000]

PM sent.

Edit: BTW, the part is definitely a service module type tank. I checked the RO config.

Edited November 6, 2015 by Nerd1000