[AR] Re: KNO3/Sucrose vs Peroxide for gas generation
- From: Lloyd Droppers <ldroppers@xxxxxxxxx>
- To: arocket@xxxxxxxxxxxxx
- Date: Thu, 26 Feb 2015 09:01:56 -0800
Monroe,
This is a function of many variables, namely pressure, concentration of
peroxide, and mixture ratio of KNO3/Sucrose. Unfortunately there is not one
answer with a volume ratio, and you should really learn how to run CEA or
ProPEP to get your answer.
But, just for fun, lets assume 85% H2O2 at 500 psi and 100% decomposition.
That is a 1370 kg/m^3 liquid, and from CEA we get 10.1 kg/m^3. So a *136-1
*ratio.
And for the sugar if I use nakka KNSU 65/35 formulation
<http://www.nakka-rocketry.net/sucrose.html> I get, 1800 kg/m^3 as cast,
and from CEA an 10.2 kg/m^3 density. so 176-1 but it is as 1690 K which is
to hot for a GG. So dropping this down to a 1200K temp, which is still
quite hot for a gas generator, at a 1.2 O/F gives 11.4 kg/m^3. So*
160-1 *assuming
the same as cast density. But you have a significant amount of K2CO3 and
some carbon in the exhaust as a liquid or solid.
So KNSU is a little higher, but it is hotter, and has a bunch of Potassium
Carbonate in the exhaust. But we obviously didn't count pressurization or
feed systems with the budget, or any grain geometry for the KNSU so these
are rough numbers only.
And if you don't mind why don't you tell us some more details about your
work that you might think a KNSU gas generator is a good idea? Because the
list is good at answering detailed amateur and small professional rocket
questions, even if as I am sure you are aware, it tends to go off the rails
occasionally.
Lloyd
projectearendel.com
On Wed, Feb 25, 2015 at 11:16 PM, Monroe L. King Jr. <
monroe@xxxxxxxxxxxxxxxxxx> wrote:
> Guy's
> I'm looking for data on gas volume generation peroxide vs KNO3/Sucrose
> I need to know the difference in volume ratio between the 2 propellants
> by weight.
>
> Monroe
>
>
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