Post by jtyotjotjipaefvj on Sept 23, 2017 14:38:24 GMT
fgdfgfthgr's propellant data sheet gave me an idea for a ship calculator that can run through many different engine configurations for a given payload and dv budget. You can force additional constraints for maximum ship cost, mass and burn time as well. It's still fairly rough and limited in the engine data department but you should be able to customize it easily on your own.
This should allow you to design new ships faster, for example if you want a light missile with high acceleration and 10 km/s dv, you can quickly see what the performance would be with different thrusters without having to manually try out all combinations. If you know your payload mass, eg. the mass of armor, control modules and weapons, just plug them into the calculator and see which engine gives the performance you want.
Post by jtyotjotjipaefvj on Sept 23, 2017 16:57:24 GMT
I added in support for tank mass and improved the suggestion display a bit. Below is a bunch of screenshots with the spreadsheet and ingame versions of the suggested missiles. The tank mass is still not quite correct but it looks to be pretty close. I'll see if I can find the error in my calculations. It also doesn't take the tank wall costs into account currently, which should be trivial to implement.
Maximum cost, mass and burn time do nothing atm? It would be great if something like this could be integrated into the game, together with graphs.
They should work fine. They only break if no configuration fulfills the requirements, in that case they just show some engine that happened to be the first in a list. The way I implemented constraints isn't very robust, so it can't deal with the case that no engine is valid.
Post by jtyotjotjipaefvj on Jan 3, 2018 11:09:08 GMT
I fixed some errors in my math that was causing errors in computing fuel tank mass, now the calculator should give exact results in all cases. I also added functionality to deal with cases when required mass ratio is higher than the highest possible fuel tank ratio, which means it's impossible to create a ship like that. I also tried to add in crude approximation for handling armor weight over fuel tank surfaces, but the math quickly gets too hairy to handle in a simple calculator like this, and anyways usually a lot of your ship surface area consists of stuff other than armor. The only viable solution is that you'll have to guesstimate and include approximate armor weight into the payload weight column.
I've also improved the UI a bit, now you're told clearly when a design doesn't fulfill the given constraints and the recommended designs view clearly shows invalid designs, as well as a separate error if no design is valid for current constraints.
The calculator is not terribly useful for designing warships, at least ones that put on a lot of armor. But for drones and missiles, this tool should be pretty useful when optimizing dv or cost. At the very least you can use it to win the micromissile challenge.
Here's the link to the new calculator version: [redacted] edit: newest version in OP
Below are screenshots of the calculator, and the highlighted ship built in game to verify that the results are correct.
Post by jtyotjotjipaefvj on Jan 4, 2018 0:12:18 GMT
I added support for MPDs, with rough approximation of required reactor mass and cost included in the combustion package mass and cost, as well as exact cost and mass for radiators required by the reactor. I use the 100 MW reactor to scale reactor mass and cost linearly to the required power draw, which is not quite correct but should be close enough for all cases. Reactor area, mass and cost are computed based on a minimal-mass amorphous carbon radiator I happened to have lying around, and should be exact for all amorphous carbon radiators as far as I can tell. I only listed stats for 100 MW and 1 GW MPDs for Neon, Methane, CO2 and Hydrogen Deuteride, but they should give a fairly comprehensive range of options, or at least enough to let you choose the MPD type you want to use.
Tests for two different cases in spoilers below to verify that the thing works correctly.
Post by jtyotjotjipaefvj on Jan 5, 2018 0:49:16 GMT
I added 10 and 100 GW MPDs to the data sheet as well as resistojets ranging from 10 MW to 1 GW. Resistojets are a bit off since you need to drop their power around 5% to get under the new TaHfC temperature limit, meaning your dv and thrust are going to be a bit lower but it shouldn't make a huge difference outside edge cases where MPDs are probably a far better choice. I also made the UI a bit different and added the option to allow engines to draw power from your payload reactors, as well as an automatic calculator that can compute reactor mass and cost if it's not included in your payload. This means you can do Deep Fryer style ships where the engines are forced to shut down when your weapons are firing, but you save a lot on reactor cost and mass.
Here's a new test with a 100 MW methane resistojet to show it gets pretty close to the right solution. With the AE resistojet the in-game ship goes up to 19.9 km/s dv, so the issue is only due to the decreased efficiency of resistojets.
Post by jtyotjotjipaefvj on Jan 19, 2018 2:43:27 GMT
I added in rudimentary armor support. The game computes armor mass a bit inaccurately so it might not give you good results, but usually the predicted design lands within 10% of the desired dv so it's usable enough. If you don't use armor, the results will be accurate.
I also cleaned the layout a bit so it's easier to add in new engines, and added support for a customizable cost function, based on which the calculator gives you recommendations. Instead of showing highest acceleration, lowest cost and lowest mass, it gives you multiple recommendations that match your requirements with varying success, which should make it easier to find good alternative designs. The cost function interface is somewhat cryptic right now but I have high hopes that you can make something out of it.