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Post by Fgdfgfthgr on Sept 23, 2017 6:42:04 GMT
The spreadsheet for all you needed to chose a propellant. All data being tested under same NTR rocket, EV=Exhaust Velocity. The EV is not the maximum EV the propellant, but that won't affect the sequence. cbhsnz-my.sharepoint.com/personal/huangy15_student_cbhs_school_nz/_layouts/15/guestaccess.aspx?docid=17813991f43e146d5a2db3b88521d1a04&authkey=Aene_piFhEsE8y_iOh9FIgcYou need to allow Excel to do Recursion to make this table work!update log: 18/10/2017 Big change: All pop. reach its maximum EV by maximum temperature! Some propellants require large throat to reach maximum EV, considered it in the table. 17/10/2017 Fixes the density of all chemical rocket fuels. Use an all-new equation to get a better result. 13/10/2017 Add some chemical rocket fuels. E.g. Fluorine-Hydrogen, Fluorine-Methane and so on. 24/9/2017 Big change: Separate each step of calculation, fix some misunderstanding of mass ratio, and you can set factors for armour and fuel tank much more clear and easy now! 24/9/2017 Fixed few bugs in the equation. Able to chose the dv you want to reach and the armour factor. 23/9/2017 A slightly more accurate equation which including the extra fuel mass added due to the weight of tanks.
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Post by tukuro on Sept 23, 2017 6:53:03 GMT
Can you upload the excel sheet through tinyupload or another alternative? This wants me to login.
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Post by jtyotjotjipaefvj on Sept 23, 2017 8:59:42 GMT
Even after logging in it says I don't have rights to access this.
Either way, not maximising EV sounds like a terrible idea if you want to choose a propellant. EV and optimized TWR are really the only things that matter. Maybe propellant density and price too, but they're usually secondary.
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Post by Fgdfgfthgr on Sept 23, 2017 9:51:33 GMT
Even after logging in it says I don't have rights to access this. Either way, not maximising EV sounds like a terrible idea if you want to choose a propellant. EV and optimized TWR are really the only things that matter. Maybe propellant density and price too, but they're usually secondary. 1. You should be able to access now. 2. The EV didn't maximise mean I didn't maximise it to the highest temperature an NTR can have, but the highest temperature of Boron Nitrate, I use Boron Nitrate to make the rocket.
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Post by jtyotjotjipaefvj on Sept 23, 2017 10:28:26 GMT
Even after logging in it says I don't have rights to access this. Either way, not maximising EV sounds like a terrible idea if you want to choose a propellant. EV and optimized TWR are really the only things that matter. Maybe propellant density and price too, but they're usually secondary. 1. You should be able to access now. 2. The EV didn't maximise mean I didn't maximise it to the highest temperature an NTR can have, but the highest temperature of Boron Nitrate, I use Boron Nitrate to make the rocket. You should use at least titanium diboride, maybe even tantalum hafnium carbide as the control rod. This information isn't really super useful if it doesn't show the best performance of each propellant. I'm not a 100% but I don't think reactor temperature affects thrust or TWR linearly, so the order of propellants might well change if you optimize the NTR. Another note is that 30 RPM is rarely the optimal choice for pump RPM. You should minimize the engine mass for the given mass flow rate and maximize the exit velocity to get the maximum performance for each fuel. I'm also not sure if you take into account how propellants affect reactor performance. The heavier propellants tend to make reactors terribly inefficient since they absorb neutrons between fuel rods. I think. For example, here's a hydrogen deuteride rocket that is cheaper than any of your 5 km/s dv rockets but gets 11.9 km/s dv and a fairly ridiculous acceleration too. According to your table I'd need 16 kc to get even 9 km/s which is clearly untrue. I'm not sure how other propellants would relate to this but you can see how your data could be very misleading. Designs in spoilers:
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Post by Fgdfgfthgr on Sept 23, 2017 10:34:17 GMT
1. You should be able to access now. 2. The EV didn't maximise mean I didn't maximise it to the highest temperature an NTR can have, but the highest temperature of Boron Nitrate, I use Boron Nitrate to make the rocket. You should use at least titanium diboride, maybe even tantalum hafnium carbide as the control rod. This information isn't really super useful if it doesn't show the best performance of each propellant. I'm not a 100% but I don't think reactor temperature affects thrust or TWR linearly, so the order of propellants might well change if you optimize the NTR. Another note is that 30 RPM is rarely the optimal choice for pump RPM. You should minimize the engine mass for the given mass flow rate and maximize the exit velocity to get the maximum performance for each fuel. I'm also not sure if you take into account how propellants affect reactor performance. The heavier propellants tend to make reactors terribly inefficient since they absorb neutrons between fuel rods. I think. For example, here's a hydrogen deuteride rocket that is cheaper than any of your 5 km/s dv rockets but gets 11.9 km/s dv and a fairly ridiculous acceleration too. According to your table I'd need 16 kc to get even 9 km/s which is clearly untrue. I'm not sure how other propellants would relate to this but you can see how your data could be very misleading. Designs in spoilers: 1. I use boron nitrate, so this sheet is boron nitrate, this table was not designed to give the best performance to all people but myself. 2. There is no unit in my xkm/s cost part. It's just relative value. 3. Neutrons did not consider because this will lead me into hard work. 4. You can give me a better equation or some enhance on readability, if not, I can't improve this table anymore.
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Post by jtyotjotjipaefvj on Sept 23, 2017 10:45:46 GMT
1. I use boron nitrate, so this sheet is boron nitrate, this table was not designed to give the best performance to all people but myself. 2. There is no unit in my xkm/s cost part. It's just relative value. 3. Neutrons did not consider because this will lead me into hard work. 4. You can give me a better equation or some enhance on readability, if not, I can't improve this table anymore. It would be useful to have total mass required, mass ratio and fuel volume for the different dv brackets. Another useful feature might be a calculator where you input required payload mass and it gives this table for the given payload so you can choose your propellant based on whether you need a small, cheap or light missile for example.
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Post by Fgdfgfthgr on Sept 23, 2017 10:54:40 GMT
1. I use boron nitrate, so this sheet is boron nitrate, this table was not designed to give the best performance to all people but myself. 2. There is no unit in my xkm/s cost part. It's just relative value. 3. Neutrons did not consider because this will lead me into hard work. 4. You can give me a better equation or some enhance on readability, if not, I can't improve this table anymore. It would be useful to have total mass required, mass ratio and fuel volume for the different dv brackets. Another useful feature might be a calculator where you input required payload mass and it gives this table for the given payload so you can choose your propellant based on whether you need a small, cheap or light missile for example. I want to have those functions, too. But how?
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Post by jtyotjotjipaefvj on Sept 23, 2017 11:31:45 GMT
It would be useful to have total mass required, mass ratio and fuel volume for the different dv brackets. Another useful feature might be a calculator where you input required payload mass and it gives this table for the given payload so you can choose your propellant based on whether you need a small, cheap or light missile for example. I want to have those functions, too. But how? I guess you'd need to record engine mass and cost by hand. After that you could compute dv and fuel mass from the required mass ratio for a given EV, then compute fuel volume and cost and add them to the engine's properties. It would be even better if there was some way to compute mass and cost for the engine automatically but I guess that's not easily doable. Recording the engine data by hand would be a hassle, but it could be made easier if you chose just a few propellants known to be good and design a number of engines with different thrust levels. Or just used Apophys's module collection.
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Post by jtyotjotjipaefvj on Sept 23, 2017 13:47:57 GMT
I made a quick mockup of such a calculator: It uses the three different types of NTR in AE modules, with thrust ranging from 10 kN to 10 MN. It's fairly easy to add in new engines and propellants but not quite zero effort. I might add in some way to input a cost function or choose what type of ship you want to make and have the sheet give you a suggestion based on that. Not sure how exactly I'd do it though.
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Post by leerooooooy on Sept 23, 2017 13:57:46 GMT
use a decent host such as google drive
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Post by Fgdfgfthgr on Sept 23, 2017 21:53:30 GMT
I made a quick mockup of such a calculator: It uses the three different types of NTR in AE modules, with thrust ranging from 10 kN to 10 MN. It's fairly easy to add in new engines and propellants but not quite zero effort. I might add in some way to input a cost function or choose what type of ship you want to make and have the sheet give you a suggestion based on that. Not sure how exactly I'd do it though. Good job!
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Post by Fgdfgfthgr on Oct 13, 2017 4:41:00 GMT
An update. Add some chemical fuels. H-F performed much better than I expect.
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Post by newageofpower on Oct 13, 2017 17:37:55 GMT
H-F is the best in terms of eV for stock chemical fuels. The only better chemical reactions (not implemented in the game) are F-LiH and O-Be. Beryllium is stupid rare (expensive) to boot, so...
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Post by Fgdfgfthgr on Oct 15, 2017 8:17:51 GMT
H-F is the best in terms of eV for stock chemical fuels. The only better chemical reactions (not implemented in the game) are F-LiH and O-Be. Beryllium is stupid rare (expensive) to boot, so... Will Francium-Fluorine work? (Joke)
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