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Post by jtyotjotjipaefvj on Sept 26, 2018 10:02:20 GMT
But in the hexagonal cow world of CoaDE, we have an additional constraint that the hot and cold side temperatures of our thermocouples cannot differ by more than ~500 K. It seems like the optimal hexcow temperature ends up being ~2630 K radiators, which is as hot as possible without reducing the ΔT across the thermocouple. The in game case is further complicated by the fact that reactor heat is incorrect. You always need to radiate the thermal power of the reactor, when in reality waste heat would be P_thermal - P_electric. IIRC this slightly lowers the optimal temperature for radiators.
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Post by AtomHeartDragon on Sept 26, 2018 19:49:28 GMT
I think this is what you meant to say. The only thing broken about laser stars is how ineffective they are. With pulsed lasers[1], fixed beam intensity[2], realistic efficiency[3] and a less limiting damage model[4], you could get one or two orders of magnitude more ablation out of your laser than you can do with the ones in game. Not to mention the unrealistic turret wobble and hard cap of 10 Mm on the lasing range. The ship might be significantly heavier and slower than what our laserstars are, but that doesn't really matter when you can kill any ship from a few dozen Mm's out. [1] Pulsed lasers can ablate armor by shattering it instead of vaporizing everything, which is far more energy efficient [2] The game has confused beam diameter and radius, which means all lasers have 1/4th of the intensity they should. [3] Real lasers can reach around 30-40 % efficiency instead of the max 4% we can do in game [4] The laser damage model in game is almost useless. It only simulates heating armor to melting point, and disregards any energy past the ablation cap of a material, so against well optimized targets, you just waste any intensity past around 4 MW/m². With enough power and big enough mirrors, you could lase targets until your effectiveness is limited by light lag instead of beam intensity falling off due to beam dispersion. Past a light minute or so of range, the target can start dodging your lasers effectively due to the travel time of the laser. True, however: - I'm not sure if turret wobble is unrealistic, especially given that it's specifically simulated and separate from the random wander of ablation point around laser's spot.
- I wonder how well those fibre lasers scale up to huge working temperatures and power densities.
- While you should be able to overcome ablation cap by dumping huge amounts of power into your melting, vaporizing and then plasmifying material, the game should take into account that it's going to be terribly inefficient. Of course you could also overcome it by pulsing, but then you should also have to watch power density in the laser as well.
- We also have one thing that works in favour of lasers - lack of threshold below which laser simply doesn't damage target.
And lastly, I really think huge orbital mirrors would be subject to treaties. It would, by the way, be cool to have a treaty layer to missions that would limit allowed technology. Of course as missions progress through the campaign treaties would end up in the garbage bin and the limitations would be gradually removed.
It would allow for some sweet custom campaigns too. Another thing, lowering the efficiency of reactors as much as possible only makes sense from a gameplay perspective. "Lets get as little power out of this as possible" said no engineer ever. When it comes to military, sacrificing efficiency for the sake of effectiveness has been always a thing. Airforce Turbofan engines are literally the opposite of efficient engines like civil airliners, so does JP-8 gulping Gasturbine engines of M1 Abrams. Having lower efficiency to get smaller, less likely to hit radiator makes perfect sense. Well, in radiators' case it's more along the lines of sacrificing energy efficiency for mass efficiency. That said, there are some problems with super hot radiators: - Many materials suffer mechanically from extreme temperatures long before they melt. COADE's safe use temperature is utterly simplistic way of accounting for that and radiators are going to suffer from mechanical issues really severely due to their shape alone. Many high power designs would in practice do something like this: *ship burns to dodge enemy fire* *ship dodges, radiators mostly stay where they were* *hilarity ensues*
- Routing super hot coolant around ship is going to be a pain, with increasingly non-ignorable amounts of heat leaking into ship's structure and systems.
- Super hot radiators are going to be problematic for surrounding hull and external components. Imagine you're a bit of ship's hull and half of your sky is a blazing wall of 2500K trying to get you up to equilibrium temperature.
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Post by jtyotjotjipaefvj on Sept 27, 2018 9:37:08 GMT
True, however: - I'm not sure if turret wobble is unrealistic, especially given that it's specifically simulated and separate from the random wander of ablation point around laser's spot.
Maybe calling it outright unrealistic is a stretch, however the issue could be mitigated by trading turret RPM for accuracy. All of our turrets have 0.09 arc seconds of accuracy, while for example the Hubble can do 0.007 with 90's tech. I'm sure in a few hundred years we could improve on that number slightly. The Hubble does take 15 minutes to turn 90 degrees, but you don't exactly need to turn in a hurry if you can kill ships a hundred Mm's away. That's yet another part of the game that could use some more attention.
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Post by AtomHeartDragon on Sept 27, 2018 9:56:50 GMT
True, however: - I'm not sure if turret wobble is unrealistic, especially given that it's specifically simulated and separate from the random wander of ablation point around laser's spot.
Maybe calling it outright unrealistic is a stretch, however the issue could be mitigated by trading turret RPM for accuracy. All of our turrets have 0.09 arc seconds of accuracy, while for example the Hubble can do 0.007 with 90's tech. I'm sure in a few hundred years we could improve on that number slightly. The Hubble does take 15 minutes to turn 90 degrees, but you don't exactly need to turn in a hurry if you can kill ships a hundred Mm's away. That's yet another part of the game that could use some more attention. Hubble is not mounted on a massive war machine full of turbopumps ramming tons of propellant/coolant per second into plumbing, thrusters performing unpredictable evasive and corrective burns, steep, changing kilokelvin temperature gradients, propellant sloshing in tanks, a lot of gimballing stuff and vibrations from impulsive shocks and tens of hairless apes flailing inside.
Accuracy VS tracking speed trade-off would be a great thing to have, but I expect situation with fast tracking turrets to be even worse than what we have now.
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Post by jtyotjotjipaefvj on Sept 27, 2018 10:51:27 GMT
Hubble is not mounted on a massive war machine full of turbopumps ramming tons of propellant/coolant per second into plumbing, thrusters performing unpredictable evasive and corrective burns, steep, changing kilokelvin temperature gradients, propellant sloshing in tanks, a lot of gimballing stuff and vibrations from impulsive shocks and tens of hairless apes flailing inside. You could mitigate most of those by using laser drones instead of capital ships. A laser satellite with a short burn time chemical laser and no engines would probably be quite cheap to produce, and would have none of these issues. Just chuck a few of them out of a bay door when you need to lase something, while your carrier continues with its maneuvering. With a large number of lasers, the individual turn rate won't be that relevant either, since you can just pop out one satellite for every target. Alternatively, if your lasers are too expensive to be disposable, you could have a small chemical thruster on the drone that allows it to catch up to the carrier after expending its lasing fuel. Probably yeah, although guesstimating the effect of improved technology might get quite difficult.
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Post by treptoplax on Sept 27, 2018 11:48:23 GMT
Also Hubble is quite different from CDE turrets in that it's a spinal mount mirror with attitude control for the whole ship controlled by (relatively tiny) reaction wheels. I would imagine that gives more precision...
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Post by AtomHeartDragon on Sept 27, 2018 12:14:48 GMT
Hubble is not mounted on a massive war machine full of turbopumps ramming tons of propellant/coolant per second into plumbing, thrusters performing unpredictable evasive and corrective burns, steep, changing kilokelvin temperature gradients, propellant sloshing in tanks, a lot of gimballing stuff and vibrations from impulsive shocks and tens of hairless apes flailing inside. You could mitigate most of those by using laser drones instead of capital ships. A laser satellite with a short burn time chemical laser and no engines would probably be quite cheap to produce, and would have none of these issues. Just chuck a few of them out of a bay door when you need to lase something, while your carrier continues with its maneuvering. With a large number of lasers, the individual turn rate won't be that relevant either, since you can just pop out one satellite for every target. Small chem-laser drones are not going to be in the same league as proper, multi MW or even GW laserstar capable of sustained fire, and with the latter going unmanned only removes the hairless apes flailing inside.
TBH I can see some good reasons for remotely operated laserstars - they are large, virtually unarmoured, pretty much incapable of dodging and perform very simple task (although OTOH you do need personnel to keep an eye on the reactors and maintain ship's systems that go through lot of abuse due to power density involved alone - might be attractive to keep them in the same hull), but this won't fix most of the problems here.
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Post by thorneel on Sept 27, 2018 20:23:30 GMT
You could mitigate most of those by using laser drones instead of capital ships. A laser satellite with a short burn time chemical laser and no engines would probably be quite cheap to produce, and would have none of these issues. Just chuck a few of them out of a bay door when you need to lase something, while your carrier continues with its maneuvering. With a large number of lasers, the individual turn rate won't be that relevant either, since you can just pop out one satellite for every target. Small chem-laser drones are not going to be in the same league as proper, multi MW or even GW laserstar capable of sustained fire, and with the latter going unmanned only removes the hairless apes flailing inside.
TBH I can see some good reasons for remotely operated laserstars - they are large, virtually unarmoured, pretty much incapable of dodging and perform very simple task (although OTOH you do need personnel to keep an eye on the reactors and maintain ship's systems that go through lot of abuse due to power density involved alone - might be attractive to keep them in the same hull), but this won't fix most of the problems here.
You could push the sacrificial laser drone idea to its logical extreme, though. Those drones have small mirrors, they must use the shortest possible wavelength. Also, they must pump as much energy as possible in the first shot, as there is no telling if they will ever get a second - and reusable lasers have their costs (changing laser fuel, cooling down, components must survive the onslaught of energy several times...) So let's use the most powerful source of the shortest wavelength possible, and not care about vaporising the drone. Yep, X-ray nuke-pumped laser warhead. The "many small tubes" may not have the range to threaten a full strategic laserstar or its secondary mirrors, but I suspect more advanced versions may, particularly as you can pack literally metres of anti-laser shielding, as long as they are X-ray transparent. And then there is also the nuke-formed projectile version which, according to matterbeam may have a surprisingly long range. Enough of those and a laserstar may have difficulties deflecting all of the projectiles. But then we are back to square one, with strategic weapons. The easiest solution to give up on military spaceship simulation and go for grand strategy space simulation...
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Post by AtomHeartDragon on Sept 27, 2018 22:36:08 GMT
Small chem-laser drones are not going to be in the same league as proper, multi MW or even GW laserstar capable of sustained fire, and with the latter going unmanned only removes the hairless apes flailing inside.
TBH I can see some good reasons for remotely operated laserstars - they are large, virtually unarmoured, pretty much incapable of dodging and perform very simple task (although OTOH you do need personnel to keep an eye on the reactors and maintain ship's systems that go through lot of abuse due to power density involved alone - might be attractive to keep them in the same hull), but this won't fix most of the problems here.
You could push the sacrificial laser drone idea to its logical extreme, though. Those drones have small mirrors, they must use the shortest possible wavelength. Also, they must pump as much energy as possible in the first shot, as there is no telling if they will ever get a second - and reusable lasers have their costs (changing laser fuel, cooling down, components must survive the onslaught of energy several times...) So let's use the most powerful source of the shortest wavelength possible, and not care about vaporising the drone. Yep, X-ray nuke-pumped laser warhead. The "many small tubes" may not have the range to threaten a full strategic laserstar or its secondary mirrors, but I suspect more advanced versions may, particularly as you can pack literally metres of anti-laser shielding, as long as they are X-ray transparent. And then there is also the nuke-formed projectile version which, according to matterbeam may have a surprisingly long range. Enough of those and a laserstar may have difficulties deflecting all of the projectiles. But then we are back to square one, with strategic weapons. The easiest solution to give up on military spaceship simulation and go for grand strategy space simulation... Based on qswitched's blog, bomb-pumped lasers seem to be poorly explored technology that's still way out there, unlike CoADE's 5' into the future stuff. Also, metres of anti-laser shielding on a drone/missile means really awful delta-v.
What could be promising is launching foil-thin foldable focusing mirrors en-masse at the target from beyond laser's effective range.
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