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Post by cipherpunks on Jan 23, 2019 21:29:09 GMT
notice that F 2 + LiH is the best-performing chemical rocket in the modded game. ^ for now. ;) What I've noticed is that Lithium Borohydride is better than LiH for NTR. It even has lower melting temperature. Lower density, though, thermally unstable (decomposes after 278C) and will eat through epoxy & nitrile rubber. iDunno (c)(tm) about LiD yet
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Post by AtomHeartDragon on Jan 23, 2019 23:24:26 GMT
Well, the current engine so far: 10m x 15m Tons: 47 Thrust: 307 MN Thrust:Mass Ratio: 668 Exhaust Velocity: 9.16km/s Gimbal: 15 Degrees And it accelerates my 5.4kt rocketship at 5.8g, and gives me 9.77km/s delta-v So I've been trying to reduce the acceleration in exchange for better engine efficiency, but I don't actually know how to do that. I assumed it would be as simple as increasing exhaust velocity - but then I'd test out higher ev and my overall delta-v would drop. Then sometimes I'd change things and my TMR might drop 20 units but that would somehow improve my delta-v by 0.20 - 0.50 km/s.
Here was my baseline:
10m x 18m Tons: 67.5 Thrust: 487 MN Thrust:Mass Ratio: 736 Exhaust Velocity: 9.15km/s Gimbal: None
Accelerates my rocketship at 9g, and gives me 9.24km/s delta-v. Which I really don't understand - it has higher TMR and thrust, and virtually equal exhaust velocity, and yet I get less delta-v out of it.
I've attached both to this post in case anyone wants to take a look.
Also, I really wish we had an option for a much smaller gimbal. I don't need 10+ degrees, just 1-3 is enough - especially with this much thrust, yet a 1-3 degree gimbal requires as much mass as a 90 degree gimbal! I'm even forced to maintain 3+ RPM even though 1 RPM will move 3 degrees in about half a second.
More or less what I'm trying to do is maintain >1.5g acceleration, fitting the engine within a 10m radius housing (either with or without gimballing), and maximizing the delta-v as much as possible.
I wouldn't mind doing away with the gimble, but I don't have a lot of room on both sides of my center of mass for lateral RCS thrusters so I'd be stuck with just a set in the nose.
5.4 G is a great way to turn your crew into a fine red paste not to mention 9 G. If you add more propellant tanks, they will increase your DV and lower your acceleration. You only really need less than 1 G of thrust to maneuver. At a typical laser engagement range of 1000km cross section matters very little. Lasers are going to hit your ship with 100% accuracy, just not your hardpoints. No reason not to add more propellant. Trained and protected humans can take about 7G along the long axis while sitting up before losing consciousness.
Laying flat on a good acceleration couch 9G eyeballs-in should pose no issues unless sustained for prolonged periods of time.
The main limiting factor for acceleration in CDE is that it's inversely proportional to the burn time, and you don't get a lot of hi-thrust burn time with CDE tech. Any thoughts on possible feasibility of using solid NTR propellant (960K T melt)? The material in question isn't that hard (27.58 MPa tensile str., 75.153 GPa Young's, 31.716 GPa Shear, 3.5 Mohs). How should this task be approached from storage/feeding PoV - would we store it pre-cut, in pellets, in fine dust form?... I'm talking about Lithium Hydride. Why not slurrify it with a propellant of choice it doesn't react with? Want deep cryogenic? LH2 slurry. Mildly cryogenic? Lower alkane slurry. Non-cryogenic? Higher alkane slurry.
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Post by cipherpunks on Jan 24, 2019 3:03:08 GMT
Light bulbs are fun you say... Shielded Superconducting Magnetic nozzles & Cooled Quartz envelopes you say... And - mostly for the sake of completeness - 233UF 6 vs. 235UF 6: That's just testing on 100 gram of 'fuel' yeah I know, injector size:RPM unoptimized, using 3.6 o expansion angle (because of multinozzle possibility) and max sane expansion ratio & neutron flux (but keeping radiation 'at bay'). Wasn't able to make 238UF 6 work in there, no criticality or it won't fit. ToDo: ponder some slurry as suggested above; look into why Syntin performs so poorly.
Edited to add: being sober, I'm not okay with this concept in CoaDE in it's current state, that is because of currently un-modelled aspects: - GCNTR apparatus has to be cooled somehow, and will melt w/o proper cooling
- magnetic nozzle has superconducting magnets which need to be powered AND cryocooled
- I believe that UF6 gas amount may need to be replenished from some tank, right?
I can't really see the way to believeably 'blackbox it in' UNLESS qswitched adds ability to slap such-and-such blackbox module ON TOP OF most modules that are already in game, e.g. adding power generation blackbox to simulate bimodal NTR, adding heat radiation blackbox to, say, rad.shield to make round radiator for the endcap SkyLab-style, electrical generator added to 'radiators' made of Black Silicon makes working backup solar panels, adding power sink (negative power delta) to cryo-tanks to simulate zero boil-off machinery, etc etc. This might go further - e.g. I'd like to have an ability to add compound armor module to radiators or crew compartment, ability to add radiator fins to railgun barrels - I believe the code will be identical. List of allowed module combinations can be instantiated akin to how limits are instantiated in current version.
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