Troy:
What about over 8%? I note that 15-16% is highest performing but that in
(amateur) practice greater than 8% proves no better. Is that your
experience too?
Bill
On Fri, Mar 30, 2018 at 7:12 AM Troy Prideaux <troy@xxxxxxxxxxxxxxxxxxxxx>
wrote:
Yup, that's the way I've always done it and my measured results (for
propellants with metal inclusions <8%) have been pretty representative of
sims.
Troy
-----Original Message-----On
From: arocket-bounce@xxxxxxxxxxxxx [mailto:arocket-bounce@xxxxxxxxxxxxx]
Behalf Of James Padfieldcomponents
Sent: Friday, 30 March 2018 9:57 PM
To: arocket@xxxxxxxxxxxxx
Subject: [AR] Re: Accounting for cured HTPB in ProPEP
So do you simply include the HTPB and the isocyanate as separate
of the formulation?are
On 30 March 2018 at 12:48, Troy Prideaux <troy@xxxxxxxxxxxxxxxxxxxxx>
wrote:
It's something I've never worried much about. The MW of a typical HTPBmolecule is in the thousands and when you react it with (say) a typical
diisocyanate, it's only the very ends (hydroxyl) of each molecule that
affected ie. none of the bulk hydrocarbon chain that we generally arefocusing
on for our thermochem.-498
Troy
-----Original Message-----
From: arocket-bounce@xxxxxxxxxxxxx
[mailto:arocket-bounce@xxxxxxxxxxxxx] On Behalf Of James Padfield
Sent: Friday, 30 March 2018 8:50 PM
To: Arocket@xxxxxxxxxxxxx
Subject: [AR] Accounting for cured HTPB in ProPEP
How do you account for cured HTPB in ProPEP and similar thermodynamic
tools?
For example, let's say I have a composite propellant with a binder
that uses
R45 HT at 5.70%, and this is cured with IPDI at 0.54%.
There are entires for R45 HT and IPDI of course, but in reality what
is present in my cured propellant is 6.24% of a cured polyurethane.
I have just noticed that there is an entry in the PEPCODED.DAF file
titled "HTPB/CURATIVE" - is this a generic entry for cured HTPB?
G 475 HTPB/CURATIVE (JOS) 656C 978H 5N 13O 0 0
.0329
Or does it not really matter and I am worrying about something that
really has no significant effect on the outcome of the calculation?
Thanks,
James