I was grilling the other day, I only grill maybe three times a year.
This thought crossed my mind on how to use charcoal in a hybrid type engine.
Now using charcoal in a rocket engine is nothing new. I was struggling with what type of binder to use.
Vegetable oil came to mind.
I remembered several years ago painting vegetable oil onto a piece of metal to try preventing rust. I came back to the metal a week or so later and found the vegetable oil had created a shellac like finish on the surface. It is a basic "drying" oil.
I have known for sometime that Linseed oil was a drying oil, as a recipe for boat patch dating to the ancients was one part linseed oil and two parts turpentine. That's an easy one to remember because the "l" in linseed oil looks like a one and the "t" in turpentine of course for two. ha
The fact that vegetable oil was a drying oil opened up new avenues, and I routinely use it for odd things I do.
Anyway, I have been thinking of grinding up some charcoal and adding just enough vegetable oil to bind the mess together.
This alone will not make good propellant. It lacks an oxidizer.
This is where the hybrid part begins.
I have a way to temporarily store oxygen in a balloon. It's a real simple arrangement. Two ball valves with a tee between them. The Tee has a balloon attached. One valve is used to fill the balloon, the other is used to release oxygen to injectors.
I have seen posts of hybrids run with balloons filled with Nitrous Oxide. The gas is injected down a central tube of the engine. I was considering using my setup to do the same.
Any comments, suggestions, or gotchas?
BBQ Engine
Moderator: Mike Everman
The benefit of using N2O is that it is safe¹ as an oxidizer until it decomposes ( (2) N2O -> (2) N2 + O2 ) It decomposes at about 450°F and thus most hybrid rocket motors contain a preheater of some sort (either a slug of normal propellant or use GOX (gaseous oxygen) and high voltage spark) Also, most hybrid rockets use liquid N2O, which is running at about -70°F and 750 PSI, not something you want to put in a balloon. If you were to use GOX you pose the problem of GOX being a fairly good oxidizer in it's current state and so it's not recommended for tinkering without very good precautions. LOX (liquid oxygen) is a whole different world compared to most rocketry. It is cold (cryogenic) and requires special *everything* that is LOX compatible(tubing, valves, tanks...everything)
The use of oil(hydrocarbon) as a fuel is common in rocketry, specially in hybrid rocketry. There are many people that are using such things as asphalt, paraffin wax, paper and things like PVC.
If you really want to delve into the world of hybrid rockets I'd suggest you joint a local rocketry group and invent in a set of SkyRipper hybrid rocket motors. They're cheap as far as rocket motors go, have a wide range of reloads (as well as the ability to make your own) from G motors in 29mm wide to K motors in 54mm wide and have very good support. If you're in the US, I've had very good luck dealing with http://www.omegahrp.com/ for my SkyRipper hardware and reloads.
Good luck!
-Aaron
¹ safe is defined as not oxidizing everything in sight. It is still a hazard for frostbite and explosive decomposition if contaminated
The use of oil(hydrocarbon) as a fuel is common in rocketry, specially in hybrid rocketry. There are many people that are using such things as asphalt, paraffin wax, paper and things like PVC.
If you really want to delve into the world of hybrid rockets I'd suggest you joint a local rocketry group and invent in a set of SkyRipper hybrid rocket motors. They're cheap as far as rocket motors go, have a wide range of reloads (as well as the ability to make your own) from G motors in 29mm wide to K motors in 54mm wide and have very good support. If you're in the US, I've had very good luck dealing with http://www.omegahrp.com/ for my SkyRipper hardware and reloads.
Good luck!
-Aaron
¹ safe is defined as not oxidizing everything in sight. It is still a hazard for frostbite and explosive decomposition if contaminated