Sciencemadness Discussion Board

Smokeless Rocket Propellant

specialactivitieSK - 7-11-2021 at 23:08

Hi. I Will use by Amateur Rocket a rocket motor from NcDeGDN Smokelles Propellant core with Pyro Booster tablet (BP+Mg+Nc) on the top of the propellant against Pulsation of the core.
Who can tell me, what diameter should have the nozzle. Thx.

Video of burning of the core with different holes :

2021-11-06-11-39-55-961.jpg - 512kB 2021-11-06-11-32-21-353.jpg - 612kB A.JPG - 931kB B.JPG - 799kB C.JPG - 995kB

XeonTheMGPony - 8-11-2021 at 03:11

I hope al those leafs are very wet, you got beyond lucky as hell no forest fire started! need a much larger exclusion area!, and perhaps sand bank.

Next need to test cores in a mock motor shell, as will behave very different.

Microtek - 10-11-2021 at 09:11

You could take a look here:

Fulmen - 10-11-2021 at 12:15

How could we possibly know? You haven't given us anything to work with.

katyushaslab - 11-11-2021 at 06:30

> NcDeGDN Smokelles Propellant core

I have absolutely no idea what you mean by this. I gather it includes nitrocellulose and something else? How is it made?

As for working out optimal core geometry, you should build what is called a "load cell" and start gathering data, plotting thrust curves with the fuel grain installed in a motor with a nozzle, etc.

Also, it looks like these are ignited from one end? For maximum thrust you want to ignite the entire core pretty much all at once.

[Edited on 11-11-2021 by katyushaslab]

Twospoons - 11-11-2021 at 12:21

You need to build a strand burner so you can run tests to work out the burn rate coefficients for your propellant. From there its just math to work out the dimensions of your propellant grain, core geometry and nozzle.

Without those burn rate coefficients, no-one can help you.

[Edited on 11-11-2021 by Twospoons]

Laboratory of Liptakov - 7-12-2021 at 06:57

The only advice is your own tests of different nozzle diameters. With the same engine body design.
If come KATO, the nozzle was small....:D

Microtek - 14-12-2021 at 00:36

I would guess that NcDeGDN means nitrocellulose/diethyleneglycol dinitrate. It would benefit from some oxidizer, IMO.