Thanks Ken, and there remains a couple of issues with end-burning
Jetex-type propellant.
First, Jetex propellants require the unobtainable
2,4-dinitroresorcinol, and second, end burn grains--even Jetex--burn
into a concave, ever increasing area, making it impossible to keep
within the +/- 10% thrust demands.
Ideas on overcoming those?
Edward
On 3/2/21, roxanna Mason <rocketmaster.ken@xxxxxxxxx> wrote:
End burner and I'll leave the propellant chemistry to someone more
knowledgeable about solid chemistry. A Jetex type GN based formulation
sounds like a good start though
K
On Tue, Mar 2, 2021 at 11:04 AM Dr Edward Jones <RocketPioneer@xxxxxxxxx>
wrote:
Pc = 50 psia, Cf = 1.15, At = 0.7 in2, Dt = 0.94", Kn = ?, F = 40 LbF.
That's fine. What propellant, and what grain configuration?
On 3/2/21, roxanna Mason <rocketmaster.ken@xxxxxxxxx> wrote:
Pressure, that's a consideration.RocketPioneer@xxxxxxxxx>
Solid propellants generally burn very slowly at atmospheric pressure,
but
how about at a somewhat higher pressure maybe 5-10% of nominal, can
they
burn stable? If so then it looks plausible.
0.1"/sec equates to a grain 'only' 60" long, is that too long?
Thought exercise:
Pc = 50 psia, Cf = 1.15, At = 0.7 in2, Dt = 0.94", Kn = ?, F = 40 LbF.
A conventional GG sounds more practical though.
GN,
K
On Mon, Mar 1, 2021 at 10:44 PM DH Barr <dhbarr@xxxxxxxxx> wrote:
Star 48's go for like 2 minutes already but they run at pretty high
pressure -- keep the geometry, upscale, slow the burn?
Granted I have no idea what a ~20ft sphere with such low thrust is
good
for, but in theory it should be possible
On Tue, Mar 2, 2021 at 12:20 AM Dr Edward Jones <
grainwrote:
Geometry is open and free to optimum design. Gas generator or
otherwise, the criteria is simply steady thrust of about 40-lbf for
about 10-min. I cannot figure a reliable way to make that happen with
any solid formulation. Help?
Edward
On 3/1/21, roxanna Mason <rocketmaster.ken@xxxxxxxxx> wrote:
Does geometry matter like diameter, frontal area? As mentionedon a
before
similar topic, I would configure such a beast as a gas generator.
If geometry didn't matter I think it can be done w/o too many
issues.
Ken
On Mon, Mar 1, 2021 at 8:07 PM Dr Edward Jones
<RocketPioneer@xxxxxxxxx
wrote:
Suppose you were assigned to design a long-burn, low-thrust solid
propellant motor with these characteristics, what would be your
configuration, case type, and general formulation:
Burn time 10-min (600 sec)
Nominal thrust 40-lbf at sea level
Operational use <10,000-ft elevation
Would your grain design keep thrust within +/- 10% of nominal?