ActionTekJackson Posted January 2, 2007 Posted January 2, 2007 Anyone have experience with these? I've been studying hybrid rockets and how they work/how to make them. and I have to say, I am completely obsessed. Here's a few websites with more information. http://users.cybercity.dk/~dko7904/motor.htmhttp://www.intertlan.com/cohetes/hybrids/tank.htmlhttp://www.ukrocketman.com/rocketry/hybrid...nce.shtml#fuels My main question is, would it work to use beutane or propane as the feul and have a solid pressed grain of oxidizer instead of doing the usual liquid oxidizer solid fuel grain method? Its just alot cheapter to get beautane or propane and solid oxidizers than purchasing LOx or N2O.
BigBang Posted January 2, 2007 Posted January 2, 2007 I have thought of using a solid oxidizer aswell, but I can't work out a good way for it to work. A rocket uses far more oxidizer than it does fuel, so the grain would need to be large. Now the grain is large and brittle, because almost all oxidizers are crystalline. But let us say we made an oxidizing grain. Now, we face injection problems. By injecting a liquid oxidizer, it doesn't matter much if you infect too much, as that'll just allow for more to be burnt if there is contact, or just a release of the oxidizer. If we were to over-inject a fuel, however, the motor would "flame out" and die. This is due to a lack of burning surface area. Since the core is the only area burning, only a small amount of oxidizer can be consumed. Should this because fuel rich, the light will turn off in the motor as it is snuffed out. N2O isn't all that hard to come by. Look around for gas suppliers, car buffs, ect. It also isn't all that expensive, when compared to AP for instance.
DeAdFX Posted January 2, 2007 Posted January 2, 2007 Another strange idea could be to have a two metal system as the fuel and a water + water soluble oxidizer (ammonium nitrate would be the best as it has the highest water solubility) and then spray boiling hot water onto the fuel grain. One of the metals would be powdered magnesium and the fuel "binder" would be a high energy eutectic mixture or a low metaling point metal. Magnesium, Aluminum and Zinc form a low melting eutectic.
ActionTekJackson Posted January 2, 2007 Author Posted January 2, 2007 I have thought of using a solid oxidizer aswell, but I can't work out a good way for it to work. A rocket uses far more oxidizer than it does fuel, so the grain would need to be large. Now the grain is large and brittle, because almost all oxidizers are crystalline. But let us say we made an oxidizing grain. Now, we face injection problems. By injecting a liquid oxidizer, it doesn't matter much if you infect too much, as that'll just allow for more to be burnt if there is contact, or just a release of the oxidizer. If we were to over-inject a fuel, however, the motor would "flame out" and die. This is due to a lack of burning surface area. Since the core is the only area burning, only a small amount of oxidizer can be consumed. Should this because fuel rich, the light will turn off in the motor as it is snuffed out. N2O isn't all that hard to come by. Look around for gas suppliers, car buffs, ect. It also isn't all that expensive, when compared to AP for instance. Hmm... you pose a good point, though I'm sure there's a solution. (i've been wrong before though) I'll have to think on this one for a bit. Now, what about melting magnesium (I know, easier said than done), and casting a grain out of it and using CO2 as the Oxidizer. I know John Wickman developed a rocket that used CO2 as the oxizer with Mg as the feul, but he had the Mg compressed with Nitrogen and injected into the combustion chamber. My thinking is carbon deposits would accumulate on the magnesium fuel grain and lower surface area eventually snuffing out the combustion. Correct?
ActionTekJackson Posted January 3, 2007 Author Posted January 3, 2007 Alright well, apparently "reverse" Hybrids do exists. Here is a reply I got from Richard Nakka when I asked him about it. Hi Jackson,Yes, "reverse" hybrid designs do exist, at least in the lab, but tend to use rather exotic oxidizers which can decompose readily to supply the needed oxygen for the reaction. cheersRichard ActionTekJackson wrote: Dear Richard,Hi, my name is Jackson Eyton, we've conversed before under my other e-mail address. I had a question for ya, not sure if you have an answer. I've been studying Hybrid Rockets and am very curious. I could simply order some N2O cartridges, and construct a hybrid motor, however, would it be possible to use a solid oxidizer grain with an injected fuel such as beutane or propane? Kind of a reverse Hybrid? I know I can't be the first to think of this, so I presume its been tried before? Any help you could provide would be greatly appreciated, thanks in advance!\ So... what constitutes as an exotic oxidizer? I used to think perchlorates and such were fairly exotic, then I grew old enough to buy them..... *shrug* Think thats what he's meaning?
BigBang Posted January 3, 2007 Posted January 3, 2007 Most likely, yes. It would need to be a volatile, organic oxidizer. Possibly some HE with an insanely high OB, possibly HNF. Rocket guys think of AP as very common, so exotic truly means exotic.
DeAdFX Posted January 4, 2007 Posted January 4, 2007 Most likely, yes. It would need to be a volatile, organic oxidizer. Possibly some HE with an insanely high OB, possibly HNF. Rocket guys think of AP as very common, so exotic truly means exotic. Hexanitroethane/tetranitromethane/Trinitromethane are some other insanely high +OB organice oxidizers. Ammonium Dinitriamide is another possiblity too.
ActionTekJackson Posted January 4, 2007 Author Posted January 4, 2007 Ahh, I'll look into obtaining/synthesizing one of those. Also, I know norco has N2O but they kinda watch you a bit here. 19 year old kid driving an '87 chevy S-10, chances are its not for his car, they're thinkin. There's been alotta hype around here about kids using N2O to get high so my guess is that's gonna be their first thought. What about using just compressed oxygen, not true LOx but simply high pressure controlled release? I've got an oxygen tank for my welding torch already anyway... I did some reading online and some kids made a hybrid rocket using everything from a hardware store. They didn't specify if they used Oxygen or N2O or not though so I'm not 100% positive. Anyone know of any problems with this?
DeAdFX Posted January 4, 2007 Posted January 4, 2007 I think GOX(gaseous oxygen) and your fuel will burn at a higher temperature than N2O + fuel. This is my only guess as to issues you might incounter.
BigBang Posted January 4, 2007 Posted January 4, 2007 Is your oxygen from bernzomatic, in a red bottle? They started selling small tanks, I think pound sized, at the Lowes by me. I'm looking into trying something with them as its cheap and easy. Maybe a cast urethane grain would suffice. The only problem would be a regulator. You need it to be sealed, then empty the tank in a matter of a few seconds. I'm sure I can get one machined. For commecial hybrid stuff, look up rattworks, contrail, sky ripper, and hypertek. Those are the main ones, and they have some good data on their motors. I'll search my computer for some hybrid data as I am certain I have a few documents, pics, ect.
ActionTekJackson Posted January 5, 2007 Author Posted January 5, 2007 Yea, I've been reading up on them and have checked out all those sites. The only thing I'd really need is the injector, I'm just not sure if I can get one of contrail's or skyripper's and use it with a home made set. I did find a yahoo group specifically for microhybrid rockets, so we'll see if they really know anything or not.
BigBang Posted January 5, 2007 Posted January 5, 2007 Microhybrids? Why don't you go to aerocon and buy theirs? Looks a little pricy, but shoudl be worth the cash. http://www.aeroconsystems.com/motors/Screa...er/screamer.htm If you buy it, you'll learn how it's made and could surely device a way to make your own. If you do buy one of them, let me know what it's like, performance, grain dimentions, injector design, et cetera.
ActionTekJackson Posted January 5, 2007 Author Posted January 5, 2007 Lol, well, if I wasn't planning on getting married I would buy it. However, I dropped a rather large hint with the folks that I want one, and my last birthday at home is coming up I'll definately let ya know if I get one, but for now I have loads of PVC to try and make my own non-reloadables.
FrankRizzo Posted January 6, 2007 Posted January 6, 2007 Why not just buy the plans for $10? http://www.qwksite.com/rlmac/rene/microhybrid/tnmh.html
ActionTekJackson Posted January 6, 2007 Author Posted January 6, 2007 Whats the fun in that? I know the technicalities of how they work, and all the parts needed. I just need to scour a hardware store and find them.
ActionTekJackson Posted January 7, 2007 Author Posted January 7, 2007 http://video.google.com/videoplay?docid=32...q=Hybrid+Rocket This is pretty much exactly what I want to make, except I want it to be able to fly so I will have to construct my own rechargable oxidizer chamber.
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