Thank you both for attempting to answer my question... I may've not all of
correctly
Thank you for the advice in where 2 post. I'm forum, and mailing list
deficient. My apologies.
What is the exact recipe for the space shuttle srbs (75\13\12?), and what
are all of the exact characteristics that are needed in Burnsim ? (I've
researched countless days looking for that information however the only way
I will find it without your help is if I learned to calculate chemical
equations that are readily posted on the internet)
On Sat, Apr 22, 2023, 5:28 PM roxanna Mason <rocketmaster.ken@xxxxxxxxx>
wrote:
Other variables are mixing different size AP, bimodal or even trimodal
like 200, 90 and 25u. It's like packing a bucket with baseballs, golf balls
and BB's, you get a higher loading density.
I have about 60Lbs of Gary's Kerr McGee 200u rotary rounded AP. A
colleague and I bought a drum a few years ago and a solid rocket project I
started couldn't be completed while living in an apartment.
Also aluminum particle size and loading affects ISP as Ferrocene and
Catocene greatly affects burn rate. You can get over an inch/sec making end
burners more practicle.
If you want any of this AP or a 5 gallon pail of Valimet H-3 spherical
aluminum contact me off list.
Ken
On Sat, Apr 22, 2023 at 10:57 AM Terry McCreary <prfesser@xxxxxxxxxxx>
wrote:
Kevin,
You will likely get more replies if you start a new thread with a new
subject line, rather than tacking a question onto an unrelated existing
thread.
The properties of APCP vary hugely with the composition. Burn rate can be
anywhere from 0.1"/s to 1"/s or even somewhat higher. Exponent anywhere
from zero to 0.6 or higher; additives can have an enormous effect. Specific
impulse from roughly 140 to 260 s. And all those figures are usually quoted
for 1000 psi; ballistic properties can be greatly---even
dangerously---different at higher pressures.
To find burn rate, a, and n.....make and burn the propellant.
Thermodynamic properties can be predicted/calculated fairly accurately from
composition. But kinetic properties generally require actual testing.
Changing to a different source for some of the ingredients? Re-testing is
almost a given. Many of those who do a lot of work with APCP often buy
ingredients in bulk to avoid concerns about different properties. (Despite
the fact that AP is a compound, 200 micron AP from Gary Rosenfield is
likely to be at least somewhat different in its behavior from 200 micron AP
purchased from, say, Skylighter or another pyrotechnics source. Morphology,
proportion of fines, etc.)
TM
------------------------------
*From:* arocket-bounce@xxxxxxxxxxxxx <arocket-bounce@xxxxxxxxxxxxx> on
behalf of kevin ward <kevinward46@xxxxxxxxx>
*Sent:* Saturday, April 22, 2023 9:30 AM
*To:* arocket@xxxxxxxxxxxxx <arocket@xxxxxxxxxxxxx>
*Subject:* [AR] Re: starship abort?
Hi everyone...
Can anyone give all propellant characteristics of Ap\Htpb+Al (BurnSim) ?
We've found all but the burn rate a, n.
Unsure if best recipe, as well. (Shuttle SRB's ?)