I think that it would be interesting to have some KP/sorbitol propellant to
start the burn
I also think that It would be feasible to modify Richard Excel file to simulate
it. Should be fun
De : sugpro-bounce@xxxxxxxxxxxxx [mailto:sugpro-bounce@xxxxxxxxxxxxx] De la ;
part de Richard Nakka
Envoyé : 27 January 2023 17:51
À : sugpro@xxxxxxxxxxxxx
Objet : [sugpro] Re: bi modal grain propellant
Very nice, Rick, I look forward to hearing how it goes. Clever way to get the
rocket off the rail quickly. Seems to be simple enough to cast in two steps.
Richard
On Fri, Jan 27, 2023 at 9:22 AM Rick Maschek <dmarc-noreply@xxxxxxxxxxxxx>
wrote:
Nikolai,
Not hoping it will work...I know from experience it will work. This is in the
testing phase to determine just how much of a change will take place in a usual
3-4 second KNSB burn and if it is worth the time and effort. Mainly for use in
our larger motors, 150--450 mm diameter 'sugar' motors.
We've done this previously with apcp propellant, this one using three different
formula propellants bonded to each other in the grains to sequentially burn
Red-White-Blue even though they had different burn rates/chamber pressures.
.: RaD <https://www.youtube.com/watch?v=oH6xE_Ej0QY> multicolor rocket
propellant static test
<https://s.yimg.com/nq/storm/assets/enhancrV2/23/logos/youtube.png>
RaD multicolor rocket propellant static test
I've also bonded different layers of 'sugar' propellant in grains to either
'top off' grains or bond segments into a single 'unigrain' by multiple pours. I
don't see a problem in the two pours bonding to each other and any pressure
drop from the faster burning KNSB+RIO to the KNSBER should be gradual to avoid
snuffing out the latter...we shall see what the tests show.
Inline image
Photo showing first pour with large mandrel removed and smaller mandrel
installed waiting for the second propellant pour.
Rick
On Friday, January 27, 2023 at 01:20:26 AM PST, Nikolai Nielsen
<nielsen.nikolai86@xxxxxxxxx> wrote:
Are you able to calculate this change into the thrust calculations or are you
just hoping it will work? Have you tried this before?
Nikolai Nielsen
On Thu, 26 Jan 2023 at 21:21, Rick Maschek <dmarc-noreply@xxxxxxxxxxxxx> wrote:
Here are a couple of grains, the one on the right is a slower-burning mix of
sorbitol and erythritol (white) that surrounds a fast-burning mix of sorbitol
and RIO for higher initial thrust off the launch pad.
Requires two mandrel sizes.
Inline image