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Post by theholyinquisition on Jan 25, 2017 17:01:32 GMT
Remember that the main reasons lasers are so dominant right now is that we built ridiculous nuclear reactors, which may not function IRL. The way I see it, we should verify reactor functionality before coming back to lasers. Yeah, how did RiftandRend power that thing?
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Post by RiftandRend on Jan 25, 2017 20:35:41 GMT
I was arguing that the game has an inaccurate representation of laser damage. Think so? I have no idea... If we assume that all of that energy is transferred to the material in reality, then yes of course the game must be wrong. But if in real life most of the energy of lasers is wasted in heat that is radiated away? The energy should be applied so instantaneously that blackbody radiation should play no part in this laser's function.
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Post by RiftandRend on Jan 25, 2017 20:37:07 GMT
Remember that the main reasons lasers are so dominant right now is that we built ridiculous nuclear reactors, which may not function IRL. The way I see it, we should verify reactor functionality before coming back to lasers. Yeah, how did RiftandRend power that thing? With a massive stack of stock 60 Mw reactors.
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Post by apophys on Jan 25, 2017 20:56:43 GMT
Remember that the main reasons lasers are so dominant right now is that we built ridiculous nuclear reactors, which may not function IRL. The way I see it, we should verify reactor functionality before coming back to lasers. Reactors are definitely not realistic because of material strengths reducing significantly at higher temperatures (I want this to be modeled). The problem can probably be solved by bracing with structural material like diamond, but any solution is necessarily heavier and more expensive than our current reactors. Probably within an order of magnitude, though.
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Post by deltav on Jan 25, 2017 21:41:42 GMT
Think so? I have no idea... If we assume that all of that energy is transferred to the material in reality, then yes of course the game must be wrong. But if in real life most of the energy of lasers is wasted in heat that is radiated away? The energy should be applied so instantaneously that blackbody radiation should play no part in this laser's function. Think about that for a sec. Laser damage primarily through heating up the atoms of the material they are focused on. So how is it that that heat will only be radiated to that one area and not act as heat normally does? A laser isn't magic, it's science. Some of the energy must be radiated away right? And when things get hot they vaporize or they melt or whatever, and just like sweating, when matter changes states, that cools things down a bit. Plus since Laser is made of light, or light like waves, some of it can be reflected. I'm not making any definitive statement here, I'm just saying that the idea that all of the energy in a laser beam will convert into energy given into the material doesn't make any sense. If that were true for starters, how is the beam even able to be built up inside the laser? If materials inside the laser can be made to reflect and deliver the beam, then the materials of ship hulls, some have mentioned nitrile rubber or some such, could obviously have a similar although reduced effect.
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Post by deltav on Jan 25, 2017 21:58:06 GMT
Remember that the main reasons lasers are so dominant right now is that we built ridiculous nuclear reactors, which may not function IRL. The way I see it, we should verify reactor functionality before coming back to lasers. Reactors are definitely not realistic because of material strengths reducing significantly at higher temperatures (I want this to be modeled). The problem can probably be solved by bracing with structural material like diamond, but any solution is necessarily heavier and more expensive than our current reactors. Probably within an order of magnitude, though. Based on naval reactors, the reactors we use in game in terms of power output per ton are right on the money with current 2016 tech and one of the most realistic parts in game. Unlike coilguns, railguns, and so on, we have tons of data avalable on naval reactors, which are pretty much exactly what would be used in space. What's not realistic is the way 100% of the MWs of a reactor is available for power... Let me explain. If we look at the newest class of carriers, they have two 41B Reactors which produce 1650 MW each and weigh about 1650 tons. Of that only about 400 MWs are so is usable for electricity. The rest goes to running the propulsion system which heats up water much in the same way as our nuclear rockets heat up propellent. So realistically how much of this power is really available to power devices on these space ships? Isn't most of it needed to heat up propellent? And what would it be like trying to maintain 40 60Mw reactors in space? That part is kind of unrealistic to me. Also where are the meltdowns? If you radiators blow up, shouldn't the ship literally melt to slag from the runaway nuclear reactions? en.wikipedia.org/wiki/United_States_naval_reactors www.navycs.com/blogs/2014/12/18/a-new-beefed-up-enginewww.unitjuggler.com/convert-power-from-MW-to-TW.html?val=1650www.alternatewars.com/BBOW/Nuclear/US_Naval_Reactors.htm
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Post by theholyinquisition on Jan 25, 2017 22:29:13 GMT
Reactors are definitely not realistic because of material strengths reducing significantly at higher temperatures (I want this to be modeled). The problem can probably be solved by bracing with structural material like diamond, but any solution is necessarily heavier and more expensive than our current reactors. Probably within an order of magnitude, though. Based on naval reactors, the reactors we use in game in terms of power output per ton are right on the money with current 2016 tech and one of the most realistic parts in game. Unlike coilguns, railguns, and so on, we have tons of data avalable on naval reactors, which are pretty much exactly what would be used in space. What's not realistic is the way 100% of the MWs of a reactor is available for power... Let me explain. If we look at the newest class of carriers, they have two 41B Reactors which produce 1650 MW each and weigh about 1650 tons. Of that only about 400 MWs are so is usable for electricity. The rest goes to running the propulsion system which heats up water much in the same way as our nuclear rockets heat up propellent. So realistically how much of this power is really available to power devices on these space ships? Isn't most of it needed to heat up propellent? And what would it be like trying to maintain 40 60Mw reactors in space? That part is kind of unrealistic to me. Also where are the meltdowns? If you radiators blow up, shouldn't the ship literally melt to slag from the runaway nuclear reactions? en.wikipedia.org/wiki/United_States_naval_reactors www.navycs.com/blogs/2014/12/18/a-new-beefed-up-enginewww.unitjuggler.com/convert-power-from-MW-to-TW.html?val=1650www.alternatewars.com/BBOW/Nuclear/US_Naval_Reactors.htmWell, for starters 1. We don't need to heat the propellant with power reactors. the NTRs do that for us, being nuclear reactors themselves. 2. SCRAM procedures are fast enough for this, I assume.
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Post by svm420 on Jan 25, 2017 22:30:21 GMT
deltav The power that is used for propulsion is provided by the core built into the NTR. We have separate reactors just for ship power. Damn space ninjas....
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Post by apophys on Jan 26, 2017 1:24:08 GMT
Based on naval reactors, the reactors we use in game in terms of power output per ton are right on the money with current 2016 tech and one of the most realistic parts in game. Unlike coilguns, railguns, and so on, we have tons of data avalable on naval reactors, which are pretty much exactly what would be used in space. What's not realistic is the way 100% of the MWs of a reactor is available for power... Let me explain. If we look at the newest class of carriers, they have two 41B Reactors which produce 1650 MW each and weigh about 1650 tons. Of that only about 400 MWs are so is usable for electricity. The rest goes to running the propulsion system which heats up water much in the same way as our nuclear rockets heat up propellent. So realistically how much of this power is really available to power devices on these space ships? Isn't most of it needed to heat up propellent? And what would it be like trying to maintain 40 60Mw reactors in space? That part is kind of unrealistic to me. Also where are the meltdowns? If you radiators blow up, shouldn't the ship literally melt to slag from the runaway nuclear reactions? en.wikipedia.org/wiki/United_States_naval_reactors www.navycs.com/blogs/2014/12/18/a-new-beefed-up-enginewww.unitjuggler.com/convert-power-from-MW-to-TW.html?val=1650www.alternatewars.com/BBOW/Nuclear/US_Naval_Reactors.htmNaval reactors do not have to worry about pushing reactor output to 2400+ K, because of the extremely convenient coolant that they sail in. So they can use a more efficient dT. Naval reactors don't use thermocouples to extract power from heat, but turbines. In a standard nuclear submarine, the driveshaft of the turbine is in fact mechanically connected to the propellers. Some ships produce all their useful energy in the form of electricity, then use that to drive propellers. Not sure how that compares in terms of weight and cost, but it is relevant. Naval reactors use pressurized water. We use liquid metal. Also relevant. Not all of the output of a reactor we have is available for electricity. In our 2400 K tungsten-osmium examples, the efficiency of converting heat to electricity is only 16.4%. Your Wikipedia link: "Reactor sizes range up to ~500 MWt (about 165 MWe) in the larger submarines and surface ships." That is 33% efficient (due to the better dT that I mentioned). Strapping a bunch of reactors together only causes issues with maintenance (modeled in our crew requirement per reactor). The CVN-65 Enterprise had 8 reactors. As a comparison of performance, we have ~1010 MWe (6210 MWt) reactors in ~10.4 tons (done by me; see the standards thread). That is 100 times better than the reactor you mention (and I suspect you meant MWt instead of MWe, which would make it ~300 times better). Part of the difference must be in safety margins, but still. On your last link, I see a bunch of reactor data that is consistently much worse than the one you mention: S6G: 165 MWt and 1680 tons. S8G: 220 MWt and 2750 tons. S5W: 78 MWt and 650 tons. 630A: 66 MWt and 312 tons. (Weirdly, the civilian one has the best heat output to mass.)
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Post by deltav on Jan 26, 2017 2:15:50 GMT
deltav The power that is used for propulsion is provided by the core built into the NTR. We have separate reactors just for ship power. Damn space ninjas.... Fine fine, but it doesn't make any sense. I think it's something added to make the game simpler. In real life think about how much care it takes to build and maintain a nuclear reactor. Having one or two is enough work. Now you are telling me you need one INSIDE each Nuclear Rocket Engine? And you need extra nuclear reactors to power your ship as well? Doesn't make any sense. Just think about it. Why are we wasting huge amounts of real estate on the ship on huge radiators when the engine exhaust can be used to both radiatate heat and provide propulsion? I'm calling a mulligan.
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Post by deltav on Jan 26, 2017 2:24:26 GMT
Based on naval reactors, the reactors we use in game in terms of power output per ton are right on the money with current 2016 tech and one of the most realistic parts in game. Unlike coilguns, railguns, and so on, we have tons of data avalable on naval reactors, which are pretty much exactly what would be used in space. What's not realistic is the way 100% of the MWs of a reactor is available for power... Let me explain. If we look at the newest class of carriers, they have two 41B Reactors which produce 1650 MW each and weigh about 1650 tons. Of that only about 400 MWs are so is usable for electricity. The rest goes to running the propulsion system which heats up water much in the same way as our nuclear rockets heat up propellent. So realistically how much of this power is really available to power devices on these space ships? Isn't most of it needed to heat up propellent? And what would it be like trying to maintain 40 60Mw reactors in space? That part is kind of unrealistic to me. Also where are the meltdowns? If you radiators blow up, shouldn't the ship literally melt to slag from the runaway nuclear reactions? en.wikipedia.org/wiki/United_States_naval_reactors www.navycs.com/blogs/2014/12/18/a-new-beefed-up-enginewww.unitjuggler.com/convert-power-from-MW-to-TW.html?val=1650www.alternatewars.com/BBOW/Nuclear/US_Naval_Reactors.htmNaval reactors do not have to worry about pushing reactor output to 2400+ K, because of the extremely convenient coolant that they sail in. So they can use a more efficient dT. Naval reactors don't use thermocouples to extract power from heat, but turbines. In a standard nuclear submarine, the driveshaft of the turbine is in fact mechanically connected to the propellers. Some ships produce all their useful energy in the form of electricity, then use that to drive propellers. Not sure how that compares in terms of weight and cost, but it is relevant. Naval reactors use pressurized water. We use liquid metal. Also relevant. Not all of the output of a reactor we have is available for electricity. In our 2400 K tungsten-osmium examples, the efficiency of converting heat to electricity is only 16.4%. Your Wikipedia link: "Reactor sizes range up to ~500 MWt (about 165 MWe) in the larger submarines and surface ships." That is 33% efficient (due to the better dT that I mentioned). Strapping a bunch of reactors together only causes issues with maintenance (modeled in our crew requirement per reactor). The CVN-65 Enterprise had 8 reactors. As a comparison of performance, we have ~1010 MWe (6210 MWt) reactors in ~10.4 tons (done by me; see the standards thread). That is 100 times better than the reactor you mention (and I suspect you meant MWt instead of MWe, which would make it ~300 times better). Part of the difference must be in safety margins, but still. On your last link, I see a bunch of reactor data that is consistently much worse than the one you mention: S6G: 165 MWt and 1680 tons. S8G: 220 MWt and 2750 tons. S5W: 78 MWt and 650 tons. 630A: 66 MWt and 312 tons. (Weirdly, the civilian one has the best heat output to mass.) Not to give you a hard time, but think about this for a sec. 1. The fact that Nuclear Aircraft carriers run in water only means they don't need cooling towers (like land based reactors), or radiators (like space based ones), besides that, there is no difference between the type reactor you would put in spaceship, and the type you would put in a sea ship. Did you notice the ship reactors in game use the exact same type of U as naval reactors? Not a coincidence. Naval reactors run hotter and therefore can be smaller, at the cost of some safety that is mitigated by being in water, in this case space. 2. You chose to focus on the Enterprise, the FIRST nuclear aircraft carrier. I get your point. But I think you missed MY point. The point of bringing up naval reactors was to show the closest equivalent to space reactors we have today, and how they perform. Surely space reactors in the very near future would be very similar if not identical. The point was to show that the idea of TW star destroyer laser arrays is kind of silly. The cost in terms of power would be ridiculous at least to me. I also wanted to be fair and show that the most modern naval reactors come close to the game reactor specs. The most up to date carriers have 2 reactors which provide about 1650 Mw of power each and weigh about 1650 tons. 3. Yes I agree that too many reactors is a bad thing. Better to have a couple big ones instead of a bunch of small ones.
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Post by deltav on Jan 26, 2017 2:44:07 GMT
apophys read some of this link on Space reactors and tell me what you think. The optimum temperature of a space reactor is just like on earth. Too hot and it melts down. Naval reactors and Space reactors have very similar requirements. They both run hotter, not because of where they are, but because they use a different kind of Nuclear Fuel, and this allows them to be smaller than they would otherwise be making them lighter. Besides that, the fact that they are in space is not as relevant as one might think (as far as I've read so far). Reactors must be kept at a steady temp no matter at space or on the ground or at sea. They require constant monitering, and refueling every decade or so. Keeping one or two up is a lot of work. Keeping 60 or more running is crazy. This was my only point. That running TWs of Nuclear reactors in space is a bit silly. Fun great fun. But nothing approaching anything like "realistic space combat". www.esa.int/gsp/ACT/doc/POW/GSP-RPT-NPS-0411%20Final%20Report%20SURE%20s.pdfwww.world-nuclear.org/information-library/non-power-nuclear-applications/transport/nuclear-reactors-for-space.aspx
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Post by RiftandRend on Jan 26, 2017 2:53:31 GMT
The energy should be applied so instantaneously that blackbody radiation should play no part in this laser's function. Think about that for a sec. Laser damage primarily through heating up the atoms of the material they are focused on. So how is it that that heat will only be radiated to that one area and not act as heat normally does? A laser isn't magic, it's science. Some of the energy must be radiated away right? And when things get hot they vaporize or they melt or whatever, and just like sweating, when matter changes states, that cools things down a bit. Plus since Laser is made of light, or light like waves, some of it can be reflected. I'm not making any definitive statement here, I'm just saying that the idea that all of the energy in a laser beam will convert into energy given into the material doesn't make any sense. If that were true for starters, how is the beam even able to be built up inside the laser? If materials inside the laser can be made to reflect and deliver the beam, then the materials of ship hulls, some have mentioned nitrile rubber or some such, could obviously have a similar although reduced effect. On second thought, radiation would play some part in the laser damage, but so little as to be irrelevant. On a laser with a larger target area it might matter more, but my laser targets over 300 Mw on a sub millimeter target. That point would become plasma in nanoseconds.
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Post by darkwarriorj on Jan 26, 2017 3:02:11 GMT
On nuclear thermal rockets: Wikipedia Atomic Rockets NASA
Nope, not just to make things simpler. It's a real concept.In real life think about how much care it takes to build and maintain a nuclear reactor. Build certainly; but I recall US nuclear submarines had reactors with lifetimes of 45 years with minimal maintenance and no down time. They'd simply replace the entire reactor once they were done with it. Chances are they'd be done with the ship in 45 years time too anyways.Having one or two is enough work. Now you are telling me you need one INSIDE each Nuclear Rocket Engine? And you need extra nuclear reactors to power your ship as well? Doesn't make any sense. Why not? Nuclear powerplants produce power in the form of heat; if you can directly use this heat then you'd do that to avoid massive inefficiencies in converting it to electricity and back to heat. Hence the NTR. We further bring more reactors to power our ship because other things need electricity...
This said, yeah. Ideally, we'd just run with a bimodal NTR, allowing the powerplants of our nuclear rockets to power our ship as well. I recall QSwitched had a reason not to put in Bimodal NTRs along the lines of too much work for too little of a difference, but it does seem that it would make a big difference now.Just think about it. Why are we wasting huge amounts of real estate on the ship on huge radiators when the engine exhaust can be used to both radiatate heat and provide propulsion? We will need the radiators for if we are not current thrusting our rocket, and if we are currently thrusting our rocket I suspect we cannot draw usable electricity from that because said heat is going out with the propellant rather than into the heat to electricity cycle. I do wonder if we can shove the waste heat from our electricity generation into the propellant before the propellant gets to the nuclear reactor though; it would be nice to be able to choose between radiators and no thrust versus forced continuous thrust but high power output.I'm calling a mulligan.
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Post by deltav on Jan 26, 2017 3:21:31 GMT
darkwarriorj I don't think you got my whole point and why I was writing and that could be my fault. In spirit I agree with almost everything you wrote in "rebuttal", but you might not see that I glossed over details and 100% facts to get to the main point. No one has time to read term papers on here right? My point was about TW laser arrays and their power requirements. But since you brought it up... 1. The designs you posted of nuclear rockets predisposes that there are no other reactors on the craft. If there are already other nuclear reactors on the vessel, it makes more sense to run propellent through the waste heat of the reactors used to generate power, and use that to provide thrust, saving strain on the radiators and wasting less heat/energy overall. That was my point. But allowing one to use the reactors sometimes just for thrust, and in other designs just for power would make design in the game much more complex. That was my point. See what I am saying? 2. About the Nuclear subs, its 13-25 years, not 45. The entire lifespan of the craft itself is 50 years or so, but not the nuclear power plant itself. That is much shorter. For reference look at this relatively recent article saying how "one day" we may have nuclear subs that can go 25 years without refueling. newatlas.com/go/7292/3. They don't replace the whole reactor, they upgrade, refuel it, etc. en.wikipedia.org/wiki/Refueling_and_overhaul4. I never was saying Space ships wouldn't need radiators. I was simply saying that it's a waste of energy to not use the opportunity of the exhaust to radiate heat and having more reactors than you need.
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