Boris, for the motor that cato'd with 3 grains and 8.5mm throat, what was
the diameter of the grain core?
On Tue, Aug 9, 2022 at 8:10 AM Boris du Reau <boris.dureau@xxxxxxx> wrote:
Hello
Find attached a recap for my silicone based propellant
I am trying to enter it in proprep and burn sim but I am getting
un-expected results.
Also looking at the KN calculation I do not understand why I had a cato
with my 3 grains and an 8.5mm nozzle . max pressure should have been around
920 PSI according to the previous burn. Are those pressures to high for
our casings?
Regards
Boris
*De :* Boris du Reau [mailto:boris.dureau@xxxxxxx]
*Envoyé :* 08 August 2022 11:47
*À :* 'sugpro@xxxxxxxxxxxxx'
*Objet :* RE: AP and PP silicone continued ....
I di some further test today with the 1 grain AP motor with 2 different
nozzle throat (4.5 mm and 6.5 mm) and recorded the thrust and pressure.
With a 4.5 mm nozzle pressure was 939PSI and it turnout to be a G107
With a 6.5 mm nozzle pressure was 240 PSI and it turnout to be an F45
See attached
I am sure that I could re-attempt a 3 grains motor with a 10 mm nozzle
*De :* Boris du Reau [mailto:boris.dureau@xxxxxxx]
*Envoyé :* 07 August 2022 18:38
*À :* 'sugpro@xxxxxxxxxxxxx'
*Objet :* AP and PP silicone continued ....
Hello All
I have managed to repair my pressure sensor with W40 and I have measured
the pressure for the following motors with ammonium perchlorate an
potassium perchlorate
38 mm 2 grains AP/Silicone with a 6.5 mm nozzle throat (see attached)
ð Pressure was 924 PSI
ð Burn time 0.8 second
ð H204 (163N) (previous tests were H206 and H224)
38mm 1 grain PP/Silicone with a 6.5 mm nozzle throat ( see attached)
ð Pressure was 544 PSI
ð Burn time 0.69 second
ð F114 (78N)
I did fire 5 time the 2 grains AP without any issue. I did a 3 grains with
an 8mm nozzle and had a cato
I did fire 3 time the 1 grain PP without any issue. I did a 2 grains with
an 8mm nozzle and had a cato.
I will try a 1 grain AP with a 4.5 mm nozzle and will re-try a 3 grains
with a 9 or 10 mm nozzle
Not sure what to do with the PP, maybe reduce the amount of PP and or
replace some of it with nitrate.
I could also add some ammonium chloride with the PP to reduce the burn
rate and the pressure.
I cannot use any of the carbonate because the silicone does not dry.
I also have some silicone drying issues with copper oxide II and my friend
Philippe has issue with Zinc
So agin base composition we are using is:
AP or PP 72.74539113
lamp black 0.332170736
silicone 1 24.23185517
Silicone 2 2.69058296
I know that the mailing list is mainly for for sugar propellant but I am
looking for advices and help to control the burn rate and pressure
I will also post the videos for the tests later on
Regards
Boris
