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Post by sweetiebot on Apr 21, 2017 3:44:26 GMT
No pic, no click  The Resistance afterburn engine may not necessary. |
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Post by The Astronomer on Apr 21, 2017 6:30:17 GMT
So you need to turn that rocket on the whole time you use the reactor?
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Post by nerd1000 on Apr 21, 2017 8:50:43 GMT
So you need to turn that rocket on the whole time you use the reactor? But you probably need to maneuver when you're fighting anyway (unless you're a doom laser jellyfish, or maybe especially if you're a doom laser jellyfish assuming ranges are long enough for random walk). Reactor can be throttled outside combat and heat dissipated through a radiator. |
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Post by Enderminion on Apr 21, 2017 12:05:56 GMT
so a bi-modeial NTR?
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Post by ash19256 on Apr 22, 2017 2:23:22 GMT
Not really, more of a nuclear reactor that can either recycle the radiator loop coolant through radiators or dump it into a thermal rocket to produce thrust, while still producing power. At least as far as I understand the picture. |
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Post by Enderminion on Apr 22, 2017 3:25:36 GMT
ok, only problem is good NTR propellants ≠ good reactor coolants
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Post by ash19256 on Apr 22, 2017 5:16:21 GMT
ok, only problem is good NTR propellants ≠ good reactor coolants Depends on what you want out of the NTR. If you want good exhaust velocity, Hydrogen doesn't totally suck at cooling things, and it's a fairly decent propellant. Really, from what I understand, most NTR propellants kind of have to be at least usable coolants, because otherwise you get the silane situation, where you have crappier performance than an equivalent chemical rocket motor. |
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Post by The Astronomer on Apr 22, 2017 5:30:26 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. |
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Post by ash19256 on Apr 22, 2017 5:33:17 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. How's it's density compare? |
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Post by The Astronomer on Apr 22, 2017 5:58:43 GMT
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. How's it's density compare? RP-1: 770 kg/m 3Decane: 730 kg/m 3Ethane: 540 kg/m 3Methane: 420 km/m 3Hydrogen Deuteride: 120 kg/m 3Hydrogen: 71 kg/m 3 |
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Post by ash19256 on Apr 22, 2017 6:00:50 GMT
How's it's density compare? RP-1: 770 kg/m 3Decane: 730 kg/m 3Ethane: 540 kg/m 3Methane: 420 km/m 3Hydrogen Deuteride: 120 kg/m 3Hydrogen: 71 kg/m 3Huh. Well, I guess it's a good in between if you want more density without going too far below 6 km/s exhaust velocity with a stock reactor. |
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Post by RiftandRend on Apr 22, 2017 13:08:03 GMT
IIRC liquid lithium is comparable to sodium as a reactor coolant and fairly good in a thermal rocket.
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Post by Rocket Witch on Apr 23, 2017 6:20:01 GMT
ok, only problem is good NTR propellants ≠ good reactor coolants Someone should mod in dihydrogen monoxide. It looks promising not only as a dual role fluid, but even for crew life support. 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. I thought the relationship between density and exhaust velocity was common rocketry knowledge... The reason I'm all like "muh density" is because reducing the mass of the armour envelope benefits a warship's delta-v more than using a fast propellant, up to a point. If you only carry nuke flash protection you probably are better off in the methane to pentane (1-5 carbon) range. |
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Post by RiftandRend on Apr 23, 2017 6:41:16 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.
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Post by Rocket Witch on Apr 23, 2017 7:08:57 GMT
I'm being facetious. Look up what dihydrogen monoxide actually is. ;)
I think it would stop being open cycle cooling and become another type of system entirely at that point, though, at least technically.
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