04-16-2018, 04:11 AM | #1 |
Join Date: Feb 2005
Location: Doncaster, UK
|
[Spaceships] Black powder Rockets?
Lagâri Hasan Çelebi was said to have made a manned ascent in a gunpowder rocket WP
Assuming this legend was true, what would be the statistics for a Spaceships black powder rocket? I can find information on the specific impulse of small modern rockets (about 80s), but I'm not sure about what this would be with 17th-century materials, and I've no idea what the thrust-to-weight ratio is. I'm imagining it would be quite low, sub 1G. Any ideas? Thanks. |
04-16-2018, 04:35 AM | #2 | |
Join Date: May 2005
Location: Oz
|
Re: [Spaceships] Black powder Rockets?
Quote:
Lots of chemical rockets have pretty good thrust-to-mass ratios, and I think that solid-fuel and hybrid rockets' mechanical simplicity means really low weight-to-thrust.
__________________
Decay is inherent in all composite things. Nod head. Get treat. Last edited by Agemegos; 04-16-2018 at 05:20 AM. |
|
04-16-2018, 04:41 AM | #3 |
Join Date: Feb 2005
Location: Doncaster, UK
|
Re: [Spaceships] Black powder Rockets?
|
04-16-2018, 06:04 AM | #4 |
Join Date: Feb 2005
Location: Doncaster, UK
|
Re: [Spaceships] Black powder Rockets?
By that, I mean, in GURPS Spaceships each rocket component gives some amount of acceleration. If a rocket gave 0.5 G, and the spaceship had three rockets, the spaceship would have 1.5 G acceleration.
When scouring for information, I've seen thrust-to-weight ratios of 3:1, 4:1 or 5:1 when discussing the minimum thrust for competitions of model rockets (the fuel for which I'm guessing is close-ish to black powder) According to the GURPS Spaceships designer's notes, 5:1 would give 0.25 G (so you'd need 5 rocket components to achieve lift off). I don't know if I'm interpreting this right, or if the figures scale up to a manned rocket. |
04-16-2018, 06:14 AM | #5 |
Join Date: May 2005
Location: Oz
|
Re: [Spaceships] Black powder Rockets?
__________________
Decay is inherent in all composite things. Nod head. Get treat. |
04-16-2018, 06:18 AM | #6 |
Join Date: May 2005
Location: Oz
|
Re: [Spaceships] Black powder Rockets?
Bear in mind that in GURPS Spaceships' terms the model rocket motors you buy consist of a engine and some fuel tanks, not just an engine. Listed thrust-to-weight ratios in the spec will be for the fully-fuelled motor at ignition, not for the almost-empty motor at flameout.
__________________
Decay is inherent in all composite things. Nod head. Get treat. |
04-16-2018, 06:22 AM | #7 | |
Join Date: Sep 2007
|
Re: [Spaceships] Black powder Rockets?
Quote:
Model/amateur rocketeers use all sorts of propellants, though, including liquid fuels. So just be sure your sources are specific. |
|
04-16-2018, 06:36 AM | #8 |
Join Date: Aug 2008
|
Re: [Spaceships] Black powder Rockets?
My understanding of black powder motors is that they are prone to cracking. That probably causes issues when you try to make something the size of an SRB. On top of that, aluminum perchlorate is far easier to cast and has a higher energy density than powder.
__________________
Buy My Stuff! Free Stuff: Dungeon Action! Totem Spirits My Blog: Above the Flatline. |
04-16-2018, 08:26 AM | #9 | |
Join Date: Aug 2007
|
Re: [Spaceships] Black powder Rockets?
Quote:
When the Mythbusters tried this in a segment called "Chinese Astronaut" or something like that their main result was scorch marks on Buster. Nevertheless, the thing you seek could be built in Ve2. When I look there I see that TL3-4 solid fuel rockets are given a performance roughly 1/5th of that assigned to TL7 types. The only way to compensate for this would be to shorten the burn time. 6 to 12 seconds instead of 30 to 60 seconds. Moving on to Spaceships I believe you would lower the Delta-V per tank by a similar percentage.
__________________
Fred Brackin |
|
04-16-2018, 09:02 AM | #10 |
Join Date: Feb 2005
Location: Doncaster, UK
|
Re: [Spaceships] Black powder Rockets?
Yes I intend to give the rocket a good chance of catastrophic failure!
|
Tags |
blackpowder, gunpowder, rocket, spaceships |
|
|