anyone have info on Nozzle-Less rockets?

[Zippiot]

:)

thanx now I will try (btw I am having a hard time finding iron oxide, some say it is at paint stores what product am I looking for?)

[El-Kablooey]

It's pretty easy to make iron oxide by electrolosis. Just use a few nails for your anode, and some aluminum for cathode. Let it run for a few hours on a battery charger and you'll have a pile of it.

[Zippiot]

I have done that many times before, made hydrogen filled water bottles...lots of fun HUGE MESS!!!

So just filter the metal and dry?

[Najm]

So just filter the metal and dry?

Heat it(the metal oxide).Loses its water of hydration or something like that.

[Greg O'Bryant]

Here are the numbers for my latest rocket candy propellant with glycerin. I started with 65 grams KNO3, 22 grams sucrose and 2 grams iron oxide. I recrytalized all of this until it was completely dry in an electric frying pan at 300. I then turned the heat down to 200 and added 11 grams of glycerin. This didn't have the consistency that I liked so I added another 4 grams. At this point it was at the right consistency like really thick brownie dough. I rolled out a few pieces so that they were about the same size as pencils and tested it. The propellant didn't burn as fast as I originally thought however it still has a really good burn rate and is easy to light. Best of all it is extremely easy to cast and you don't have to estimate the proper moisture content like on Jimmy Yawns web page ie "the snap test".
So a good mix may be as follows

KNO3 64%
Sucrose 20%
Glycerin 14%
Iron oxide 2%

[Greg O'Bryant]

I just tested the propellant in the previous post the 64/20/14/2 ratio's as it wasn't exactly like the first on I made. It was a little dryer so that now it was a crumbly solid that packs together very well like slightly damp clay this makes it perfect fro tamping the propellant into engine cases as always it has decent burn characteristics.

[Najm]

I made an end burner motor(4 inches) using epoxy as fuel, threw a flame 6 inches long behind it but it didn't produce much thrust.Maybe I was using the wrong type of epoxy(steel).But the 6 inch long flame indicates there was a good pressure buildup in the motor.

[larry cottrill]

But the 6 inch long flame indicates there was a good pressure buildup in the motor.

Najm -

Possibly not as much as you might think. The length of flame suggests to me you're getting really good velocity - but, for example, our pulsejets will throw flame 4 inches or more, and there's very little pressure there (max. ~ 2 atm absolute).

The low thrust may mean that the high flow speed isn't matched with a high massflow rate, and for thrust you need BOTH massflow and speed. If your flame is straight (not spreading as it separates from the straight bore of the motor), you're basically operating just above atmospheric pressure, and the motor would theoretically benefit from some type of nozzle (even if fairly "open", i.e. low restriction). If the flame is spreading significantly, you have "excess pressure" and could benefit from adding a reasonably long, slightly tapered expansion cone (like the rear end of a deLaval nozzle) blending smoothly into the motor bore. (However, if you actually had much excess pressure, I think you'd already be seeing some reasonable thrust development.)

L Cottrill

[Ray]

I made an end burner motor(4 inches) using epoxy as fuel, threw a flame 6 inches long behind it but it didn't produce much thrust.Maybe I was using the wrong type of epoxy(steel).But the 6 inch long flame indicates there was a good pressure buildup in the motor.

I would expect that if you wanted to do a nozzle-less motor you'd want to put a core in it. You'll increase the burning area, AND build more mass into the flow. I don't think you'll make it where you want to be with just an end burner...unless you have a VERY fast propellent. Something that measures its burn rate in the INCHES per second...Most propellent is much slower than that.

I have burned bates grains on the ground (for a 75mm motor) and gotten 18-24" flames out of BOTH ends of the grain. Quite a lot of fun to do.

[Zippiot]

SO I'll need to do some calcs to see how long it needs to be to make sufficient thrust and burn time.

Im starting to steer away from the nozzle-less b/c it seems that you would need a super long sugar motor, a propellant that burns as fast/faster than bp, or a 3-5 inch diameter motor. None of which seems really appealing...but I may be able to work with the really long sugar motor around a 2 inch diameter....

[Najm]

It was a cored end burner.Very slow burn rate, must have burned for at least 15 seconds.
Nozzles used to decrease velocity and increase pressure and thrust.

[MJD]

Sugar rocket fuel burns very slowly int he absence of pressure, but once it gets up to pressure it burns like crazy! Composite fuel "chuffing" is when the fuel and nozzle are mismatched so that the correct pressure is not achieved, the fuel chokes itself out/down. I have found much info on nozzleless rockets (solid fuel) except!!! the type of fuel used. It must be fast burning and very hot, I assume bp is the standard but to my surprize many ata missles are nozzleless composite fuel. This may be b/c of what Larry said about already having supersonic flow...

Which air to air missiles exactly are nozzleless?...

However, the GTR-18A Smoky Sam training round is nozzleless and of composite propellant - Google it. And the propellant is not "hot", in fact in terms of composite propellants the opposite is true. But it is fast burning, and it has been massaged a bit to burn more stably at lower chamber pressures. Not hard to do.

Ray Goodson's nozzleless rockets, of which videos can be found on the Aerotech website, were magnificent efforts and he reached some serious altitudes.

[Zippiot]

The meteor (or one of the rockets made by the same company) uses a nozzle-less rocket which turns into a ramjet.

http://www.bayernchemie-protac.com/meteor.htm

I guess its not the meteor, but I'll leave that up just because.

[MJD]

The meteor (or one of the rockets made by the same company) uses a nozzle-less rocket which turns into a ramjet.

http://www.bayernchemie-protac.com/meteor.htm

I guess its not the meteor, but I'll leave that up just because.

Okay, these I know about. Boosted to flight velocity by a nozzle less rocket but sustained by ramjet. Not pure nozzle less rocket but close enough!

[Ves]

Nozzleless rocket motor: Diameter D:24mm (~1") L=120mm (~5")
Propellant: KNO3/Su 60/40 Recristallized - 70gramms
Rocket - D:40mm L:600mm -start weight 375gr.
Max altitude (apogee) 325m ~1000feet

Video:(1,71 MB)