kkerros
what you have described is a rocket engine,(finally a question directally aimed at my degree w00t)
LH2 + LOX at that
last i checked LH2 has a density of 0.07 give or take
so very not dense (means 1kg of it is really really big)
a stoichiometric mix of LH2/LOX will burn at something like 8000k i think at 400PSI or so.
tantalium carbide has a melting point of ~3500k
space shuttle operates at an F/O ratio of 6/1 (IE 6 parts H2 to 1 part O2, by mole) to get the temp down and the exhaust velocity up, at 1000PSI chamber pressure it runs at 4500F or so i believe. They also run the worlds most stupidly powerfull axial flow turbo pump as an expander cycle to power the thing.
on that note a substantial ammount of combustion happens outside the chamber as the remaning 5 parts of O2 and other assorted sub species react with atmospheric O2.
On the upside theres no smoke at all, its just water vapour once all's said and done. (perhaps some CO and nitrogen compounds as a result of it burning in the atmosphere but its not like its going to fill an arena)
Wax hybrids are still in their infancy, you dont have the problems with regression rate and nozzle blocking that you get with HTPB or say salami but you do have problems with heat soak melting your fuel grain. LOX + wax hybrid could make an explosive mixture if molten wax mixed with LOX (it wouldnt be intimate mix so it wouldnt "detonate" but i sure wouldnt want to be standning next to it), so you are down to NOx / wax and still have to solve the melting problem. Your typical hybrid propellant however dosent burn all that fast so you wind up with long skinny fuel grains which is not nifty.
LOX + Hydrocarbon is much easier to use in many respects and offers much better density. Downside is LOX + Hydrocarbon mix = detonation hazard.
EG LOx + asphalt + truck driving over it ~= boom.
all your LOX parts must be cleaned for oxygen service which isnt the end of the world but can be a pain in the ass, you also have to make sure all your valves are LOX compatiblle so only teflon or viton seals. You have to make sure you have no metal parts in any tubing that will see a decent flow velocity as the friction of the particles hitting the wall can cause stainless steel to ignite.
Fire Fighting procedure for a fire involving LOx consists of
Remove LOX if possible
Protect sorounding buildings/objects
you dont even bother with whats on fire its just going to burn.
also the rules specifically state no oxidisers allowed
otherwise we would already have a LOX/NOx hydrocarbon powered drum/disk spinner ;-> _________________ Mechanical engineers build weapons, civil engineers build targets
Fri Dec 09, 2005 6:12 pm
Big AL Experienced Roboteer
Joined: 16 Oct 2004
Posts: 436
Location: roleystone perth. WA
well since you cut metal by heating it up with a
Flame
i would say its a flame weapon. _________________ For West ausies interested in robotics email me at: theoneshrug@hotmail.com
OR
dragoonarie@gmail.com
best quote ever:: "Those Gas-Turbine style warehouse heaters arent illegal, and neither is remote controlling one as far as I know."
Joined: 31 May 2004
Posts: 3160
Location: Melbourne, Australia
I was all for building a Rocket backpack to replace the Gyrocopter, until I discovered that they since the first model back in the 60's, they had managed to increase the flight time by 50%..
from 20 seconds to 30 seconds
That dampened my enthusiasm somewhat.. $300 for Hydrogen Peroxide used in 30 seconds didnt sound like much fun at all..
I did a fair bit of research on different fuels and specific impulses and things while checking it out, no degree, but probably enough knowledge to blow myself up spectacularly if I tried..
Sidetrack - I think the Rocketdyne F1 engine is possible one of the coolest pieces of engineering ever accomplished by man..
http://en.wikipedia.org/wiki/F-1_(rocket_engine)
Have you head of Peter Plichta and his "Silane Oils" ?
http://www.plichta.de/english/english.php?patents
Sounds a bit quackish, but interesting. perhaps you can shed some like whether hes being a duck or not ? I havent heard of anything recently from him. Interesting idea doing chemistry by the mathematical models of prime numbers
If we diverge too much into rocketry, I'll split the thread out of the rules section.. _________________ Great minds discuss ideas. Average minds discuss events. Small minds discuss people
Fri Dec 09, 2005 9:53 pm
Valen Experienced Roboteer
Joined: 07 Jul 2004
Posts: 4436
Location: Sydney
"conventional wisdom" says that mollecular weight is god
silicon is heavier than carbon so it'd want to release an assload of energy to make it worthwhile.
as for air breathing launchers they look really good untill you see the size of the jets you need to get enough lift that your upper stages will work.
currently the only air launch setup working that i know of is pegasus (orbital type stuff, Rutans mob and white knight is also air launch but it isnt orbital (as yet))
personally
i think his thrust to weight is going to be way off, the thing wont be able to get off the ground. _________________ Mechanical engineers build weapons, civil engineers build targets
Fri Dec 09, 2005 10:39 pm
Giant Robo Experienced Roboteer
Joined: 17 Jun 2004
Posts: 583
Location: Marayong NSW
OMG! Is Jake talking shit again?
Sat Dec 10, 2005 12:35 am
cerberus3112
Joined: 05 Dec 2005
Posts: 497
Location: Mt Druitt,Sydney,NSW
but with a plasma torch dosent have a flame it has a beam of plama _________________ A journey of a million miles begins with a single step followed by a hell of a lot of other steps so get walking
quote:Originally posted by cerberus3112:
but with a plasma torch dosent have a flame it has a beam of plama
Yeah sure go ahead and make a bot with a plasma torch...
I would just love to see how he gets his opponent to sit still while he clips the earth lead on.
Hmm wonder if that would be an entanglement device or a tethered weapon, probably doesn’t mater as UltiBot’s is the only local comp where a plasma torch is legal anyway and there both legal there anyway as I read it.
Sat Dec 10, 2005 11:47 am
Valen Experienced Roboteer
Joined: 07 Jul 2004
Posts: 4436
Location: Sydney
thats a plasma cutter wot needs earth
you can make a plasma *torch* with no earth lead
i think a mag is a better application of 60A than the plasma torch however.
although.... cool++ _________________ Mechanical engineers build weapons, civil engineers build targets
Sat Dec 10, 2005 12:10 pm
Rotwang Experienced Roboteer
Joined: 15 Jun 2004
Posts: 1589
Location: Vic
I might concede that you can make a plasma torch where the earth lead attaches to the torch not the material you are trying to destroy.
They have a tendency to get rather hot and are normally liquid cooled but one running off batteries in a 30kg bot is probably going to last as long as the batteries.
A lot of effort to blow a bit of hot gas at an opponent and difficult if the bots are around 10 meters away and facing the wrong way around.
I think hosing the opposition down with petrol and setting fire to them has a better chance.
Sat Dec 10, 2005 4:52 pm
dyrodium Experienced Roboteer
Joined: 24 Aug 2004
Posts: 6476
Location: Sydney
XD your secret plan eh?
Actualy just out of interest, is petrol a legal fire weapon? I think green eye silver dragon used it but im not sure... its certainly a dirty flame but cheap! (well... not that cheap anymoreXD) _________________ ( •_•)
It seems to work well in Frogie land when it comes to disposing of excess citrones.
Sat Dec 10, 2005 5:45 pm
Spockie-Tech Site Admin
Joined: 31 May 2004
Posts: 3160
Location: Melbourne, Australia
Is there any such thing as a Citroen this *isnt* suplus to requirements ? _________________ Great minds discuss ideas. Average minds discuss events. Small minds discuss people
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