Nikolai,
The highest pressure I've run a motor successfully was a 75mm motor at 1,200
psi. We unintentionally CATOed a couple of larger motors when they reached
2,000 psi.To reduce CATOs, we now try to keep our pressure (depending on the
motor case) below 800 psi.What little gain in Isp by running at high pressures
is more than offset by the number or risk of CATOs. If we need more Nsec for a
project we simply use a larger (length, diameter, or both, case. If we need
higher Isp, we use APCP.
Rick
On Thursday, November 19, 2020, 06:34:36 AM PST, Richard Nakka
<richard.rocketry@xxxxxxxxx> wrote:
Nikolai,I would limit your motor design max pressure to around 1000 psi
(6.9MPa) for the simple reason that the sugar propellants have not been
characterized (burn rate in particular) at pressures much higher than this. At
2000 psi, it's anyone's guess as to how the propellant will burn.Richard
On Thu, Nov 19, 2020 at 6:03 AM Nikolai Nielsen <nielsen.nikolai86@xxxxxxxxx>
wrote:
on a pyrotechnics forum i posted to, one guy said: this From all the research
I've read increasing the case pressure on sugar fuel beyond 1000psi results in
zero net gain of total impulse. The fuel reaches a plateau where increased
pressure does not increase its isp.do i just leave it at 1000 psi ( ~7MPa)?
Nikolai Nielsen
On Thu, 19 Nov 2020 at 13:02, DH Barr <dhbarr@xxxxxxxxx> wrote:
What is the particular reason for wanting to run your sugar motor at 2400 psi?
Have you considered what that means for heat?
On Thu, Nov 19, 2020 at 4:00 AM Nikolai Nielsen <nielsen.nikolai86@xxxxxxxxx>
wrote:
i got the alloy type.
http://asm.matweb.com/search/SpecificMaterial.asp?bassnum=MA6063T6 . im using ;
this calculator
the working pressure is 16.8 in MPa
can i run an aluminium cased motor with 38mm od and 3mm wall thickness at this
pressure?Nikolai Nielsen
On Thu, 19 Nov 2020 at 01:49, Rick Maschek <dmarc-noreply@xxxxxxxxxxxxx> wrote:
This will help you get there...you need to look up the yield strength for the
formula.
Barlow's Formula - Internal, Allowable and Bursting Pressure
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Barlow's Formula - Internal, Allowable and Bursting Pressure
Calculate pipes internal, allowable and bursting pressure
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On Wednesday, November 18, 2020, 03:32:34 PM PST, Nikolai Nielsen
<nielsen.nikolai86@xxxxxxxxx> wrote:
I have aluminium tubing of the 6063 / 6082 alloys measuring 40mm od, 3mm wall
thickness. I want to find its accurate burst pressure so I can use it to make a
sugar rocket motor, can anybody help me find the correct figures?
Nikolai Nielsen