[WIP]Nuclear Salt Water Rocket dev thread

[FreeThinker]

Yep. I certainly derped on that one. Though, 3200 fuel was assuming the fuel has the same density as regular LiquidFuel; the NuclearSaltWater fuel have only 1/5 of the density.

Also, I'm planning to rescale everything to 3.75m. Specs on the OP. Need rebalancing on fuel tank capacity; right now, the tank is a Jumbo-64 upscaled by 150%.

Notice that most mods use the 1Unit = 1Liter standard. It keeps things simple and less confusing, especialy when converting resources. NuclearSaltWater is mostly made from Water, which uses the 1L/1U standard, like all Communty Resources.

[shynung]

Notice that most mods use the 1Unit = 1Liter standard. It keeps things simple and less confusing, especialy when converting resources. NuclearSaltWater is mostly made from Water, which uses the 1L/1U standard, like all Communty Resources.

The NuclearSaltWater density is identical to CRP's Water; I literally copied part of CRP's config on water.

Current stats are 2160 units of NuclearSaltWater for a 3.75m tank made out of an upscaled Jumbo-64. Is this close enough?

Also, somehow the part cost becomes minus when the NSW tank is filled. I may have tweaked the resource cost too much; what did I miss?Fixed; forgot a dot in the unitCost variable.

Edited September 2, 2015 by shynung

[shynung]

Just got the chance to try it out in a test mission in-game and...

Damn, it's OP. It emptied its fuel tank in about 30 seconds, pushing it into a trajectory whose periapsis was inside the Sun.

Will post screenshots later.

[ThatOneBritishGuy...]

If you'd like I can make a new model for the engine and tanks as well as original textures (If you'd like of course). PM me if you're interested.

Edited September 3, 2015 by ThatOneBritishGuy...

[shynung]

Wonderful. PM is sent.

[FreeThinker]

Would be cool if he could tubed tanks. Perhaps something that looked like this:

[shynung]

Doesn't have to be that complicated. Textured cylinders are enough. Besides, why would anyone store uranium-salted water in a bundle of pipes exposed to the elements? One MMOD strike, and there goes the rest of the deltaV.

Though, I think having tanks in multiple sizes, say half-length, quarter-length, and one-eighth-length would be useful.

[FreeThinker]

Doesn't have to be that complicated. Textured cylinders are enough. Besides, why would anyone store uranium-salted water in a bundle of pipes exposed to the elements? One MMOD strike, and there goes the rest of the deltaV.

Though, I think having tanks in multiple sizes, say half-length, quarter-length, and one-eighth-length would be useful.

True, but this model does show that square tanks would be a logical storage shape as it allow you to fold the tubes in twie dimentional way. If you would remove all air in between the tubes, I would have a perfect storage device for Uranium Sallted Water.

[shynung]

It's not trivial, but possible, to construct a cylindrical pipe-bundle tank which uses a much simpler construction method: arranging the pipes into a sheet (think of radiator plates), then rolling the sheet-of-pipes into a cylinder. Cover it with a corrugated plate that do double duty as radiator and debris shield, and you have a pipe-bundle tank that looks similar to typical KSP propellant tanks.

[ThatOneBritishGuy...]

Alright first bit of progress on the engine. I tried to make the overall figure as unconventional and intricate as possible (due to its unique nature) while still keeping the feel of the stock NERVA.

The engine has no gimbal motor (though with a bit of work I can change that), so the three ringlike structures on the engine bell are just there for looks.

This is pretty much the final colour scheme. I tried to go for a more stockalike appearance, and I think in that regard it looks pretty good. Do note however that the textures you see here are not final.

The tank butt is included in the engine, but I can omit it rather easily so it's up to you if you want it to be part of the engine or not.

Fits to 3.75m parts.

Edited September 4, 2015 by ThatOneBritishGuy...
Those darn spoiler tags get me every time XD

[shynung]

Alright first bit of progress on the engine. I tried to make the overall figure as unconventional and intricate as possible (due to its unique nature) while still keeping the feel of the stock NERVA.

http://i.imgur.com/Qkp54tA.png

The engine has no gimbal motor (though with a bit of work I can change that), so the three ringlike structures on the engine bell are just there for looks.

http://i.imgur.com/1BGs1VV.png

This is pretty much the final colour scheme. I tried to go for a more stockalike appearance, and I think in that regard it looks pretty good. Do note however that the textures you see here are not final.

http://i.imgur.com/R43Pvuy.png

The tank butt is included in the engine, but I can omit it rather easily so it's up to you if you want it to be part of the engine or not.

Fits to 3.75m parts.

Nice work! That looks really cool.

I'd say keep the tankbutt. It seemed like almost every other engine has it.

Edited September 4, 2015 by shynung

[FreeThinker]

Not bad, it is starting to look like this design for a Nuclear Salt Water Rocket

The model should represent the very powerfull nature of the engine

Perhaps you could increase the width of model and widen the exit of the nozzle to 3.75m diameter

Edited September 4, 2015 by FreeThinker

[ThatOneBritishGuy...]

So something more like this?

[shynung]

That's the ticket.

[regex]

The NuclearSaltWater density is identical to CRP's Water; I literally copied part of CRP's config on water.

The density should probably be changed. Note that water has a density of @ 18 g/mol while uranium tetrabromide (quoted as the salt here) has a density of @ 558 g/mol. If you use the 2% mass mixture quoted in the linked PDF (and I did my math correctly) you get a salted water density of @ 28.81 g/mol. This means that the density of your salted water should be 1.6 times that of water.

[shynung]

The density should probably be changed. Note that water has a density of @ 18 g/mol while uranium tetrabromide (quoted as the salt here) has a density of @ 558 g/mol. If you use the 2% mass mixture quoted in the linked PDF (and I did my math correctly) you get a salted water density of @ 28.81 g/mol. This means that the density of your salted water should be 1.6 times that of water.

Thanks for the input. Implementing.

[ThatOneBritishGuy...]

So I'll just post here with a new pic and the information that the model is now finished.

Cheers

[FreeThinker]

Yes, it's looking better, but what are those tubes and extension mend for? Cooling? When generating an Isp of 6700s, the core temperature would have to be 100,000 K The biggest problem would be to get all that power though a nozzle throat . That way I think in contrast to chemical rockets the nozzle throat needs to be much wider, otherwise you will meld the throat in a matter of seconds. It will also require some extreme cooling. This means you need a significant amount of power during operation and a large array radiators to get rid of the Wasteheat.

Edited September 17, 2015 by FreeThinker

[shynung]

Yes, it's looking better, but what are those tubes and extension mend for? Cooling. When generating an Isp of 6700s, the core temperature would have to be 100,000 K The biggest problem would be to get all that power though a nozzle throat . That way I think in contrast to chemical rockets the nozzle throat needs to be much wider, otherwise you will meld the throat in a matter of seconds. It will also require some extreme cooling. This means you need a significant amount of power during operation and a large array radiators to get rid of the Wasteheat.

Maybe you meant chamber temperature, since a nuclear salt-water rocket doesn't actually have a reactor core.

Right now, engine heat production config is 4 times of LV-N's. Does this need adjustment?

Also, uploaded engine models to github repo.

Edited September 13, 2015 by shynung

[ThatOneBritishGuy...]

FWI, you have both the old and the new engine texture in the respiratory.

[MatterBeam]

I've been following this, and I'd like to make a tiny note:

AFAIK, Zubrin's original NSWR proposal stated that heat management would not be much of a problem, since the enormous mass of water flowing out of the nozzle would provide open-cycle cooling. In fact, the main challenge to obtaining a high-thrust, high-isp low waste heat GW-range rocket was twofold:

-Maintaining reaction stability. This is assumed to be an extremely complicated balance of fuel flow, chamber water streams and uranium density hitting the exact critical spot.

-Funding a project that literally dumped tons of radioactive water per second.

The hard thing for you here is that, like the Orion, it is an extremely powerful piece of technology that is near-impossible to balance in a game.

My proposals/suggestions:

-Convert the drive into a three part assembly: a very large water-circulation chamber, a dense uranium-enriched water fuel tank and a relatively lightweight reaction nozzle.

-Use RealFuel's 'fuel stability' system to manage the water chamber. Sudden movements would disrupt the flow and risk a catastrophic criticality in places you don't want. Players would have to stabilize the chamber before firing the rocket, on top of the mass and volume difficulties.

[NuclearNut]

You should also make the rocket have massive problems should the fuel tank be introduced to the surface fast enough for it to disintegrate, this being HEU dissolved in water and stored in tightly packed tubes. Should a tube smash open, or lots of tubes smash open... well you would have a possibly prompt critical fission reaction emitting tons of heat and huge amounts of radiation in places you would not want it, killing the mission.

[MatterBeam]

You should also make the rocket have massive problems should the fuel tank be introduced to the surface fast enough for it to disintegrate, this being HEU dissolved in water and stored in tightly packed tubes. Should a tube smash open, or lots of tubes smash open... well you would have a possibly prompt critical fission reaction emitting tons of heat and huge amounts of radiation in places you would not want it, killing the mission.

I guess a very low impact tolerance would be sufficient to portray this problem.

[shynung]

FWI, you have both the old and the new engine texture in the respiratory.

Whoops. Fixed.

Still working on the attachment nodes. RL stuff is tying me down lately.

I've been following this, and I'd like to make a tiny note:

AFAIK, Zubrin's original NSWR proposal stated that heat management would not be much of a problem, since the enormous mass of water flowing out of the nozzle would provide open-cycle cooling. In fact, the main challenge to obtaining a high-thrust, high-isp low waste heat GW-range rocket was twofold:

-Maintaining reaction stability. This is assumed to be an extremely complicated balance of fuel flow, chamber water streams and uranium density hitting the exact critical spot.

-Funding a project that literally dumped tons of radioactive water per second.

The hard thing for you here is that, like the Orion, it is an extremely powerful piece of technology that is near-impossible to balance in a game.

My proposals/suggestions:

-Convert the drive into a three part assembly: a very large water-circulation chamber, a dense uranium-enriched water fuel tank and a relatively lightweight reaction nozzle.

-Use RealFuel's 'fuel stability' system to manage the water chamber. Sudden movements would disrupt the flow and risk a catastrophic criticality in places you don't want. Players would have to stabilize the chamber before firing the rocket, on top of the mass and volume difficulties.

So basically, large and heavy tanks that hold only small amounts of propellant despite their mass and size, and a relatively lightweight rocket engine. This, in addition to the engine not having a bottom attachment node, being bulky, and costing quite a fortune. Or, make the engines as expensive as the stock 3.75 m first-stage engine, but make the propellant tanks expensive and fragile. Didn't understand the bit about water circulation chamber, what would that be used for? Cooling?

[FreeThinker]

Maybe you meant chamber temperature, since a nuclear salt-water rocket doesn't actually have a reactor core.

Right now, engine heat production config is 4 times of LV-N's. Does this need adjustment?

Also, uploaded engine models to github repo.

I'm getting the feeling you do not fully comprehend the amount of power you are dealing with here.

Let me show you.

First let's calculate the amount of power for a stock NERVA engine

The stock NERVA produces 0.050 * 800 * 9.80665 * 0.5 = 0.181 GW This might seem a lot until you compare it to the Nuclear Salt water reactor

The Amount of power produced by your Salt Water Engine equals 2.150 * 6728 * 9.80665 * 0.5 = 70.930 GW !!

That means your Nuclear salt core reactor will produce 391 times the heat of a NERVA!!! So if you want to do it fair, you would have to multiply your heating by this amount. If you do, you will notice the engine will instantly explode the moment you start to increase throttle.

Lt's assume you engine is extremely efficient and is has an efficiency 99%, that means you still have to deal with 709 MW!!

Now this is going to require some extreme engineering.

Are you starting to feel the heat?

Edited September 18, 2015 by FreeThinker