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OtherBarry

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Posts posted by OtherBarry

  1. (emph. added)

    Wait, what? Why would that be? My understanding was that pressure vessels scale linearly in mass with the volume of propellant they contain, and that the utilization scales pretty much normally. Also if you mean decreasing efficiency, I think you mean increasing *dry* mass...

    What *does* have a big impact on utilization is the aspect ratio of the stage: short, fat stages have much lower utilization than tall, skinny stages because of the domes of the capsule tank-shaped pressure vessels.

    Ah, that post was based on rather limited research that I'd picked up while trying to recreate realistic rockets. I'm sure you know a lot more than I do about this. My main thought was that once your tank got larger than say first stage Saturn V tanks, surely you would need more support than just tank walls in order to prevent the whole thing from falling apart, or imploding.

    Also, after rereading the Tsiolkovsky rocket equation, it turns out I may have misinterpreted the reason for staged rockets, its actually for two reasons, firstly, that when a stage gets large enough, there is more dry mass than having a smaller tank and smaller engines in a new stage. Secondly, because thrust required for liftoff can cause g-force problems when its pushing a practically empty tank.

  2. Why would those limits be necessary? I do not think there it much of a problem in real life building a huge tank. Sure, it will be a big task, but the forces are all well understood.

    I would rather be challenged with real challenges :)

    You are sort of correct there. IRL tanks are sort of limited in size, in that the larger the tank, the less of its total volume is fuel, which increases wet mass, decreasing efficiency. This is an important factor in building rockets, as it essentially gives you the maximum volume of a tank before its more efficient to add another stage. That seems to be incorrect. See NathanKell's post below.

    That being said, currently this mod does its best to stick to the stock way of implementing, such that more science = bigger fuel tanks. I assume it will stay that way, although hopefully there will be an equivalent to the 'utilisation' feature of the latest stretchy tanks, to help in realism.

  3. Hi.

    First time poster, long time lurker.

    Just wondering if you could give me any tips on how to scale up a custom fairing base to make it 10m diameter(editing .cfg or otherwise)?

    My Ares V and SLS look a bit awkward with tapered conics matching up to an 8m base.

    Thanks!

    If you look into the cfg files you should be able to see two things changing, the 'rescaleFactor' and certain numbers in the NODE lines. If you look at how these change from say the 4 to the 6 to the 8 meter variants, you should be able to extrapolate how you would change them for a 10m variant.

    Then all you need to do is copy one of the smaller ones, change it to the stats of a 10m one, and then change all the names to 10m rather than whatever you copied it from, save it to the same location, and it should work.

    Or you could just use the procedural interstage with a nosecone on top.

  4. I have been running stretchsrb, realfuels , jacks eng configs. will it be straight forward to me to switch over the PP????

    Not yet unfortunately, I'd stick with StretchySRB v9 until there is proper RealFuels integration, which should (hopefully, swamp_ig is doing quite a bit at the moment) be next update. Currently RealFuels thinks a 5x5m tank has the same amount of fuel as the the stock Oscar-B tank. I switched about two weeks ago and haven't been able to play with any of my realism stuff since :( , although it did give me a reason to do another stock career mode runthrough.

  5. I assume so. No idea how easy this is, as swamp_ig and NathanKell do most of the coding, I just help out. Once the procedural trusses are working, it should be fairly simple to apply the same shapes to a tank but it depends how easy procedural trusses are to code on the first place. Not entirely sure if thats the direction the mod is heading though, as I think its branching out into different types of procedural parts; trusses and heat shields and such.

  6. Is there already something that rescales the KW rocketry SRBs? If not, would people be interested in one? So far I've made a fairly realistic GEM 46 (Delta II SRB) using the Globe I, and kind of realistic (about 18t to heavy) Atlas V SRBs using the Globe IV and V. Still looking to see if the other boosters are based on IRL ones.

    EDIT: Just realised the RFTS engine pack does somewhat rescale them, but they aren't based on realistic boosters. Unless I've missed an update RealEngines doesn't seem to do this. Has anyone else tried it?

  7. Btw could we get more shapes than circular? triangular, square, penta, hexa, etc, set the number of faces 3+, would also be nice to have the choice of picking the end-cap textures, and the foil looking ones should have end-caps with the same texture as the rest of the tank.

    Structural trusses are somewhere in the development line, after fixing the current structural part, and probably after full RF/MFT integration. I assume changing the number of faces on a truss wouldn't be too hard to implement.

    Choosing end-cap textures would be cool, but probably fairly low in importance. In the meantime you can just make a cone with 0.01 thickness and 0.01 top diameter to make it look the right texture.

  8. Forgive me if this has been mentioned already... But the SRB's don't seem to work with deadly reentry... The temp bounces around right near max for a while then finally explodes from overheating. Even tweaking max temp to a ridiculously high number in the cfg doesn't seem to help.

    There's an issue about this on the GitHub page, so essentially heat production scales with thrust and size in about the same way the stock SRB's do. I personally don't like this because if you go much larger than stock ones it will just explode. I don't have access to KSP at the moment, but I think you can change the heat output in one of the proceduralpart modules in the SRB cfg file.

  9. I think having a dedicated set of configs for real fuels would be the way to go.

    That would make sense. I do often forget that people play KSP without the whole realism suite.

    If there is going to a separate RealFuels config, you may want to increase the efficiency and/or volume of the SRB's as, although i still need to properly test this, they seem really underpowered.

    EDIT 1: After some testing with RealFuels installed, I changed the atmosphere SRB to an Isp of 260-280 and that gives about the same delta v as the stock RT-10, if I scale the SRB to the same dimensions as the RT-10, however with a much smaller amount of fuel. I will do more testing, but I do suggest increasing the volume or the Isp of the SRB at the moment.

    EDIT 2: After a clean install, purely stock+procedural parts, A procedural SRB of the same size as an RT-10 will run out of fuel ~3 seconds earlier than, while a procedural SRB with the same fuel will cut off at the same point, but weighs 0.04t (very close, well done on that count) but is 0.725m (~27%) longer, which isn't that far off, but probably what triggered my underpowered reaction.

    EDIT 3: The BACC edition. Firstly, three unrelated bugs I have discovered in my testing. A) With SAS on or off, and with gimbal on or off, a ship that is just Procedural SRB+Payload will wobble around, while a stock SRB+Payload rocket will stay perfectly straight SAS on or off. B) on occasion, if not using launch clamps, a stretched tank will occasionally spawn part way through the launch pad, and will promptly explode when the physics kicks in. IIRC stretchy tanks also had this issue, although I believe that was fixed somehow. C) I can now only change the SRB thrust tweakable in the hundreds using the << or >> buttons, as the smaller ones do nothing, and the slider just always resets to the lower hundred.

    Anyway, back to the BACC. So oddly enough a procedural SRB the size of the RT-10 will have about 20% less fuel than its stock counterpart, but when comparing the procedural SRB to the BACC, the procedural SRB has >30% more fuel. In flight testing, the procedural SRB (with a slightly lower thrust, 300-315) outperformed the stock SRB of the same size by ~16s (47-63). A procedural SRB with the same fuel as the BACC is a massive 1.625m shorter, and (still with a lower thrust, so its actually underperforming) outperformed the BACC by about 1 second.

    If this is helpful/important, I'm happy to do more testing. Otherwise I'll probably still do it (It's surprisingly fun) I just wont clog the forum with it.

    Thanks for making this awesome mod, btw.

  10. RealFuels:

    As for real fuels instead of having real fuels be aware of ProceduralParts events we should do like StrechyTanks does which is call ChangeVolume().

    if (part.Modules.Contains("ModuleFuelTanks"))

    {

    try

    {

    ...

    part.Modules["ModuleFuelTanks"].SendMessage("ChangeVolume", (newVolume));

    ..

    }

    catch (Exception e)

    {

    print("*PP* changing volume, caught: " + e.Message);

    }

    }

    My testing shows RF is smart enough to change mass of the tank as you strechy it for you.

    Ah. This is well outside my modding abilities, although I was going to suggest something like that. Also on the real fuels note, is the plan to stick with the current 2 tank system (Liquid Fuel and RCS) or something similar to stretchy tanks with Cryogenic/Balloon/Service module/etc? So far I'm using the default RF module for the liquid fuel tank and service module for the RCS tank, though I think I'll change it to cryogenic tank and then a hypergolic ballon tank/service module hybrid, as thats what I used most with stretchy tanks.

    As for radial decouplers, there is a somewhat realistic one in the NovaPunch pack, can't remember the exact name of it, but its the long one. I doubt you will be able to find real life examples as most of them are built specifically for each rocket.

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