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Post by gyratron on Jan 29, 2019 0:53:35 GMT
Now that's a big gun. If you can keep your distance, you could probably own laserstars with it (although I wonder if they could shoot down those rounds?). That said, it might be more effective than it would be in reality, see below. After much searching I still haven't been able to find an EM gun with a monolithic projectile which can crack a gunship straight through the nosecone, something which saboted rounds achieve easily. Some very high muzzle velocity railguns in the 0-200g range can make a bunch of black tiles on the front, but they never seem to achieve anything much when they get in. I wonder if this is because a saboted projectile would really be that effective, or because hypervelocity collisions between "payload" rounds are modeled incorrectly. Given the results so far, I'd guess the latter, since the system was meant to be used in collisions between starships or missiles, not projectiles going that fast. Hypervelocity impact physics are a very different beast from regular impacts, and while they seem to be simulated for monolithic rounds, it's likely that for payloads, this isn't considered. As far as I know, sandblasters should be pretty useless against heavily slanted whipple shields. Mass is what determines how hard is it to change velocity of the projectile, so a sub-gram round should, in most cases, bounce off a gunship's nose. I don't think payloads are modeled much differently from projectiles, if there's even any difference at all (it should be very easy to test this if you really want). You've got to remember that the bore radius of these needles is always much narrower than the bore of the barrel, even hundreds of times narrower for the more ludicrous railguns. A narrower projectile will encounter pressure from that much smaller an amount of whipple shield, so it makes sense that making a penetrator long and thin would have a significant effect on whipple shield penetration as well as it's obvious benefits against conventional armor. Projectile shape and size is taken into account for both payloads and projectiles, that I know for sure. Whether the simulation of those effects works for sub-gram projectiles less than a millimeter across and whether you have a sabot which could actually keep a payload like that in one piece until the end of the barrel is a different matter of course. On top of that there doesn't seem to be much real-world data on impacts of this size above about 10km/s anyway, so I wouldn't expect too much fidelity in the 100km/s+ region.
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Post by cipherpunks on Jan 29, 2019 1:05:13 GMT
Projectile shape and size is taken into account for both payloads and projectiles, that I know for sure. Elaborate please. What is your source for this information?
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Post by airc777 on Jan 29, 2019 4:15:50 GMT
1.59Mm/s, 9.58Mm capital range estimation, 1.51Gj projectile energy. Switched to boron filament barrel armor to maintain accuracy. I join the club of the slow traverse turrets.
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Post by airc777 on Jan 29, 2019 4:53:25 GMT
1 kg projectile, 380 km/s, 2.29 Mm capital range estimation, 145 Gj projectile energy. Had to use diamond barrel armor to maintain accuracy. For when you just reeeeeally have to ruin somebody's day.
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Post by airc777 on Jan 29, 2019 15:00:15 GMT
Attached ship has five 10Mm needle guns, five 2Mm / 1kg projectile needle guns, ten 1Mm 66.4ms needle guns, ten 250Mw/m^2@1Mm lasers, and ten 1.36Gw/m^2@1Mm lasers. The ten big guns are set to target ships and not shots, everything else can target both ships and shots. I normally like to proof my ships armor profiles against their own guns but I have no idea at all where to begin to stop a 1kg projectile. Frontal cone has 1cm of osmium, 1m of graphite aerogel, and 10m of UHMWPE fiber. Underneath the frontal cone and covering the entire ship is my normal armor profile for stopping 15mj needles and my own not very optimized lasers. Crew modules have 2cm of amorphous carbon and are buried in the middle of the ship, reactors are under the frontal cone. Ship has 10 times the radiator area it needs and 20 times inter reflection, all radiators are boron nitride or carbon carbon.
Unrelated, but I'm thinking about building a large scale railgun to fire nuclear missiles at 50 to 100 km/s with ten seconds of burn time on the missiles, to see if I can make a missile that can close the distance on my laserstars.
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Post by gyratron on Jan 29, 2019 17:02:10 GMT
Projectile shape and size is taken into account for both payloads and projectiles, that I know for sure. Elaborate please. What is your source for this information? This blog by Qswitched childrenofadeadearth.wordpress.com/2016/06/24/what-to-shoot/discusses the effects of varying the width on projectiles, and as I mentioned earlier I have tested the principle on payloads with needlers by swapping the needle for a disc (with a spacer added to maintain exit velocity) and observing a massive decrease in performance against sloped armor for the same impact velocity.
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Post by AtomHeartDragon on Jan 29, 2019 17:57:36 GMT
Elaborate please. What is your source for this information? This blog by Qswitched childrenofadeadearth.wordpress.com/2016/06/24/what-to-shoot/discusses the effects of varying the width on projectiles, and as I mentioned earlier I have tested the principle on payloads with needlers by swapping the needle for a disc (with a spacer added to maintain exit velocity) and observing a massive decrease in performance against sloped armor for the same impact velocity. Has anyone tested this with non-payload slugs? Say, same mass, same material ferromagnetic slugs fired at the same velocity - one plate shaped fired from RG, the other needle shaped fired from CG. Rate of fire and accuracy matched adjusting power draw and slapping on the right amount of barrel armour. Also matched tracking speed. Preferably also for high and low velocities (say 2 and 10km/s).
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Post by cipherpunks on Jan 30, 2019 3:17:45 GMT
Ship has 10 times the radiator area it needs and 20 times inter reflection, all radiators May I ask what are Your PC specs? Here, viewing this ship in editor becomes 1 FPS lag fest, and degrades to 0.25 FPS if I try to edit something. And this is (older generation) OC'd TotL i7, cool, with decent GPU and good RAM...
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Post by airc777 on Jan 30, 2019 4:00:09 GMT
Ship has 10 times the radiator area it needs and 20 times inter reflection, all radiators May I ask what are Your PC specs? Here, viewing this ship in editor becomes 1 FPS lag fest, and degrades to 0.25 FPS if I try to edit something. And this is (older generation) OC'd TotL i7, cool, with decent GPU and good RAM...I7-6700k, stock clock, H80i gt cooler. 2x8 ddr4 2666, underclocked to 2133. GTX980ti sc, stock clock, over volted fans. 120gb sata6gbps ssd. Monitor is 60hz 1080p.
Editor works fine, having trouble myself loading it into sandbox. Not sure why, I've done dumber things.:
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Post by tetraflon on Jan 30, 2019 4:23:47 GMT
A slightly lighter 1 Mm/s needler. Most of the mass savings come from the 0.1 deg/s turning speed, but it is a lot more efficient too. At least it's cheap enough to realistically mount on a ship. Can you build one fires 1g needles?
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Post by airc777 on Jan 30, 2019 4:53:36 GMT
A slightly lighter 1 Mm/s needler. Most of the mass savings come from the 0.1 deg/s turning speed, but it is a lot more efficient too. At least it's cheap enough to realistically mount on a ship. Can you build one fires 1g needles? 1 gram, 1 Mm/s, 1Gj, 1Gw, 1degree/s, 6Mm.
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Post by cipherpunks on Jan 30, 2019 8:50:00 GMT
I7-6700k, stock [...] 2x8 ddr4 2666, underclocked to 2133 Well, mine is 360mhz less on turbo, and no AVX2 instructions. I guess - judging from current technical state of this game - that the culprit is clock only, but - as I do like stock voltage - I refuse to push this rock further. What memory latency this 2133mhz underclock gives, I wonder... My experience was diametrally different: editor was laggy as hell, sandbox - only when intercepting further out than 0.9 Mm; I managed to partially de-lag it by upping reactors to 11.6 GW, reconfiguring overcool to be only 3x with less panel quantity (this seemed to be most resultative), changing propulsion from many 10-way engines to less 19-way ones, and changing most of the tanks from 100kt/20 to 200kt/40 (no mods, just limits). Oh, and changing lesser railguns from needlers to regular ones (despite somewhat inferior performance) also seemed to help, but here I may be wrong.PanzerschiffLessLag.txt (12.05 KB) With regards to internal volume, and thus armor mass/area, it is preferable to have 19x innermost tanks, not 20x. Outer ones can be 20x no problem. Edit: Funny, this Osmium armor cone has visual glitch I haven't seen earlier:
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Post by airc777 on Jan 30, 2019 9:31:06 GMT
Turns out it's an absolute bear to get a railgun with a 10Mm range or anymore then 1.6Mm/s velocity. Once you go past about 1.6Mm/s the capacitor charge time ramps up sharply from ~2 minutes to ~10 minutes to force feed the projectile the last little bit of velocity. Don't miss your first shot or the laserstar will win. Additionally this seems to be near the limit of what zirconium copper rail material can handle without shattering and what any material other then diamond can handle as barrel armor. I could not for the life of me make a 2Mm/s gun without limits editing.
Finally bothered to put a mpdt on a ship. Please ignore the 101y burn time.
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Post by airc777 on Jan 30, 2019 9:35:50 GMT
What memory latency this 2133mhz underclock gives, I wonder... System wasn't stable at 2666 at time of build even though motherboard said it supported it, was probably fixed in a bios update that I just haven't bothered to download. That or it just needed a hair more voltage and I didn't care enough at the time to try.
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Post by jtyotjotjipaefvj on Jan 30, 2019 10:00:05 GMT
With some mild limits editing (increasing barrel length and armor thickness) you can make far faster guns too. Without changing the barrel length, you don't have enough space to keep the stresses low so I doubt you can do it very effectively at least. These types of guns have the additional benefit that lasers have a hard range cap of 10 Mm. Once your range is noticeably above that, cost or mass don't really matter that much since no laser star will be able to retaliate.
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