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Post by ironclad6 on Sept 1, 2017 21:03:37 GMT
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Post by Kerr on Sept 1, 2017 21:05:51 GMT
You get 3.51TW waste heat from neutrons and x-rays. With a good structure you can let 99% of the radiation escape |
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Post by ironclad6 on Sept 1, 2017 21:12:53 GMT
In lore the Whiskers will probably wind up being MPDT driven but I've not yet decided on that for sure. As for the game, I like the pretty exhaust trails so I'm keeping it. Also the Valkyrie Orbital Drop ships are MPDT driven.
Edit to add, yeah in lore they would have to be MPDT driven. It doesn't make sense to expend times the energy to get the same performance.
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Post by Kerr on Sept 1, 2017 22:02:51 GMT
In lore the Whiskers will probably wind up being MPDT driven but I've not yet decided on that for sure. As for the game, I like the pretty exhaust trails so I'm keeping it. Also the Valkyrie Orbital Drop ships are MPDT driven. Edit to add, yeah in lore they would have to be MPDT driven. It doesn't make sense to expend times the energy to get the same performance. I've always assumed that for heavy armed fusion ahips an MPDT would provide thrust in combat. If your p-B11 10,000km/s engine produces 1G for you an MPDT (50% MHD) would give you 5G at 1,000km/s. If your fusion acceleration is 0.1G then 500km/s will give you 1G, 250km/s 2G, And 125km/s 4G. And if you have 80% Efficiency, based on the german redearch study, the thrust will increase even more. If you have 6Mm/s Dv and utilize 10% of fuel for MPDT-Boosting you get 5.4Mm/s Delta-v. 540km/s. Which are exactly 3 hours of 5G bursts. |
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Post by ironclad6 on Sept 1, 2017 22:52:35 GMT
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Post by ironclad6 on Sept 1, 2017 23:45:25 GMT
In lore the Whiskers will probably wind up being MPDT driven but I've not yet decided on that for sure. As for the game, I like the pretty exhaust trails so I'm keeping it. Also the Valkyrie Orbital Drop ships are MPDT driven. Edit to add, yeah in lore they would have to be MPDT driven. It doesn't make sense to expend times the energy to get the same performance. I've always assumed that for heavy armed fusion ahips an MPDT would provide thrust in combat. If your p-B11 10,000km/s engine produces 1G for you an MPDT (50% MHD) would give you 5G at 1,000km/s. If your fusion acceleration is 0.1G then 500km/s will give you 1G, 250km/s 2G, And 125km/s 4G. And if you have 80% Efficiency, based on the german redearch study, the thrust will increase even more. If you have 6Mm/s Dv and utilize 10% of fuel for MPDT-Boosting you get 5.4Mm/s Delta-v. 540km/s. Which are exactly 3 hours of 5G bursts. The simple answer is that I have to accept the lower efficiency so I can make use of the heat sinking effect. Essentially, if I generate fusion power and then use that power to feed an MPDT then I have to radiate away whatever heat I gain through inefficiency. This is essentially impossible for the level of thrust I want to develop. Even though a five to one efficiency boost from switching to MPDT would permit me to reduce my drive power needs five fold, that still doesn't get the heat problem even close to being under control. If on the other hand I simply use a series of interlocking magnetic field as a nozzle and let those fusion products vent to space they carry most of their troublesome heat with them and I only have to radiate away the remainder. This is less effective at small scales such as drones etc, but for the Crater Class tenders, I can't find a way to get their heat generation under control using an MPDT. |
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Post by Kerr on Sept 2, 2017 0:13:19 GMT
I've always assumed that for heavy armed fusion ahips an MPDT would provide thrust in combat. If your p-B11 10,000km/s engine produces 1G for you an MPDT (50% MHD) would give you 5G at 1,000km/s. If your fusion acceleration is 0.1G then 500km/s will give you 1G, 250km/s 2G, And 125km/s 4G. And if you have 80% Efficiency, based on the german redearch study, the thrust will increase even more. If you have 6Mm/s Dv and utilize 10% of fuel for MPDT-Boosting you get 5.4Mm/s Delta-v. 540km/s. Which are exactly 3 hours of 5G bursts. The simple answer is that I have to accept the lower efficiency so I can make use of the heat sinking effect. Essentially, if I generate fusion power and then use that power to feed an MPDT then I have to radiate away whatever heat I gain through inefficiency. This is essentially impossible for the level of thrust I want to develop. Even though a five to one efficiency boost from switching to MPDT would permit me to reduce my drive power needs five fold, that still doesn't get the heat problem even close to being under control. If on the other hand I simply use a series of interlocking magnetic field as a nozzle and let those fusion products vent to space they carry most of their troublesome heat with them and I only have to radiate away the remainder. This is less effective at small scales such as drones etc, but for the Crater Class tenders, I can't find a way to get their heat generation under control using an MPDT. Yes, the difference in waste heat is enourmous. The 7.5TW are nothing compared to 1PW, but I didn't really meant your ships but fusion ships in general. Which reallistically travel at few hundred milligees. You really did dodged a bullet by choosing p-B11 with its pure thermal radiation. D-He3 at 25Mm/s produces 25% X-rays and neutrons. Which result in 0.4% of the thrust power ending up as as heat. Combined with the inefficiencies of the magnetic nozzle. |
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Post by The Astronomer on Sept 2, 2017 3:29:43 GMT
Can I have that magnetic confinement 'material'?
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Post by ironclad6 on Sept 2, 2017 3:55:51 GMT
Can I have that magnetic confinement 'material'? I've only abstracted around it. My maths isn't that good. Or rather, I have not yet devoted my full attention to that particular problem and I wanted to get back to writing. In any case, the specifics of the "material" vary wildly depending on specifics like precise field geometry, super conductor material, power input and so on. I will work it out if I really need to down the road. |
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Post by bigbombr on Sept 2, 2017 7:08:53 GMT
... AGDA is a 100 ton 80% zubrol driven missile with a 2.5 megaton fusion boosted nuke warhead. They're used against capital ships and surface targets where collateral damage is considered acceptable or where a point needs to be made. Aside from that there's your bunker buster and your anti-armour missile. I think I might give up on Zubrol to be honest. If it were me I'd accept the acceleration disadvantage before I'd roll around in a multi-gigaton nuclear bomb. Why use the warhead? Zubrol detonates on impact (in game, IRL it would probably still detonate, but not very efficiently). All the water also means you don't generate a heatflash like a conventional nuke, but a steam powered concussive blast, which definitely isn't something spaceships are used to handle. |
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Post by Kerr on Sept 2, 2017 9:31:27 GMT
... AGDA is a 100 ton 80% zubrol driven missile with a 2.5 megaton fusion boosted nuke warhead. They're used against capital ships and surface targets where collateral damage is considered acceptable or where a point needs to be made. Aside from that there's your bunker buster and your anti-armour missile. I think I might give up on Zubrol to be honest. If it were me I'd accept the acceleration disadvantage before I'd roll around in a multi-gigaton nuclear bomb. Why use the warhead? Zubrol detonates on impact (in game, IRL it would probably still detonate, but not very efficiently). All the water also means you don't generate a heatflash like a conventional nuke, but a steam powered concussive blast, which definitely isn't something spaceships are used to handle. Depends on if you use 20 or 90% UTB Zubrol. 20% UTB gives you 470kg TNT for every kg of fuel. At 90% you get 2.75kT. You either have a wavefront moving at 66km/s or 0.015c. |
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Post by bigbombr on Sept 2, 2017 9:42:13 GMT
Why use the warhead? Zubrol detonates on impact (in game, IRL it would probably still detonate, but not very efficiently). All the water also means you don't generate a heatflash like a conventional nuke, but a steam powered concussive blast, which definitely isn't something spaceships are used to handle. Depends on if you use 20 or 90% UTB Zubrol. 20% UTB gives you 470kg TNT for every kg of fuel. At 90% you get 2.75kT. You either have a wavefront moving at 66km/s or 0.015c. Unless it's a cassaba howitzer or a H-bomb, I wouldn't bother with a warhead if you're using 90% Zubrol. |
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Post by Kerr on Sept 2, 2017 10:43:44 GMT
Depends on if you use 20 or 90% UTB Zubrol. 20% UTB gives you 470kg TNT for every kg of fuel. At 90% you get 2.75kT. You either have a wavefront moving at 66km/s or 0.015c. Correction: 0.00015c. It's not your speed/light speed * 100, but just your speed/light speed. 4.7Mm/s divided by 300Mm/s is?... |
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Post by The Astronomer on Sept 2, 2017 10:59:24 GMT
Correction: 0.00015c. It's not your speed/light speed * 100, but just your speed/light speed. 4.7Mm/s divided by 300Mm/s is?... Hmm... Damn. |
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Post by Kerr on Sept 2, 2017 11:06:06 GMT
Depends on if you use 20 or 90% UTB Zubrol. 20% UTB gives you 470kg TNT for every kg of fuel. At 90% you get 2.75kT. You either have a wavefront moving at 66km/s or 0.015c. Unless it's a cassaba howitzer or a H-bomb, I wouldn't bother with a warhead if you're using 90% Zubrol. If I have 90% UTB zubrol I woudln't bother using explosives at all. An 100t NSWR missile with 50t dry mass achieves 1% of C. You could carry 40,000x und 1kg submuntions easily with it. Zubrol submunition don't sound that good, if you hit one submunition every submunition inside a kilometer radius explodes too. |
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