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Post by newageofpower on Apr 23, 2017 8:12:50 GMT
In my experience, nukeflash armor is best when carrying HD, while thin-medium armor is suited for Methane. Medium/thick armor you want decane or RP1.
You can get decent EV out of heavier hydrocarbons with encapsulated fuel, but if we're doing mods Metalized Hydrogen and Graphene encapsulated fuel crushes everyone else.
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Post by Enderminion on Apr 23, 2017 14:27:00 GMT
you got me, I was thinking about dioxygen hydrogen, if thats even possible
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Post by n2maniac on Apr 23, 2017 19:45:00 GMT
So namely 2 features claimed: - Be able to reject waste heat from a nuclear generator to an engine's reaction mass
- Be able to have a resistojet use pre-heated reaction mass
Correct?
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Post by sweetiebot on Apr 25, 2017 12:59:32 GMT
Wait, are we approaching this from the wrong angle? We don't need to use the reactor coolant as the propellent, we can just use a heat exchanger and transfer the energy to a fuel holding tank before the engine. Yep,that right, I make some mistake on pic is the heat pool should be name as " heat exchanger", and cryo propellent will by pass that and take waste heat away. And make sure cold bath still cold.
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Post by sweetiebot on Apr 25, 2017 13:05:31 GMT
So namely 2 features claimed: - Be able to reject waste heat from a nuclear generator to an engine's reaction mass
- Be able to have a resistojet use pre-heated reaction mass
Correct? Right, that what I thinking for. The engine's can use NTR or any type thermal rocket.
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Post by matterbeam on May 3, 2017 16:13:56 GMT
Metalized Hydrogen and Graphene encapsulated fuel crushes everyone else. What's the mass ratio/density of graphene-encapsulated fuel? The only obvious issue I see with OP's design is that hot gasses coming straight of a reactor will need ultra-strong piping made out of refractory materials.
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Post by zorbeltuss on May 3, 2017 16:58:41 GMT
you got me, I was thinking about dioxygen hydrogen, if thats even possible Hydroperoxyl is possible, and fairly common in some instances, getting data on it would probably be harder, but it could possibly be useful. ^^ About this system, well the reactor would get very high efficiency with hydrogen or helium but I doubt there would be a good thermo couple combination that would stand up to the thermal stresses of using either of them.
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Post by goduranus on May 3, 2017 18:35:18 GMT
It could use ethane, as mentioned above, which is a good outer loop coolant for reactors under 500MW level, while is also quite good propellant.
I guess the name of this thread should be Intelligent Thermal Resource Management, the advantage of such being:
More thrust from a given engine size at all times, depending on reactor thermal output;
More reactor power while main engines are active, due to cooling by expended propellant.
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Post by newageofpower on May 3, 2017 18:35:54 GMT
you got me, I was thinking about dioxygen hydrogen, if thats even possible Hydroperoxyl is possible, and fairly common in some instances, getting data on it would probably be harder, but it could possibly be useful. ^^ About this system, well the reactor would get very high efficiency with hydrogen or helium but I doubt there would be a good thermo couple combination that would stand up to the thermal stresses of using either of them. Differentially doped graphene. Its a technique that works with tungsten, though efficiency is compromised. EDIT: Ideally we'd use turboelectric power, of course. With graphene ; )
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Post by underwhelmed on May 3, 2017 20:09:44 GMT
ok, only problem is good NTR propellants ≠ good reactor coolants Yeah... Sodium NTR's exhaust velocity is ~2.8 km/s... Ethane fares better at ~5.8 km/s, though... Wait a minute. Ethane performs better than both decane and RP-1? My ethane engine got much higher exhaust velocity and thrust with the same reactor core than both RP-1 and decane. RP-1 yields slightly lower exhaust velocity than decane, but with much higher thrust. Yes, ethane is the most efficient at converting reactor power into propulsive power.
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