Probably my favorite quote from my favorite book.
- Rick Dickinson
On December 1, 2015 3:04:14 PM PST, Doug Jones <djones@xxxxxxxx> wrote:
"A monopropellant is a liquid which contains in itself both the fuel
and
the oxidizer…. But! Any intimate mixture of a fuel and an oxidizer is a
potential explosive, and a molecule with one reducing (fuel) end and
one
oxidizing end, separated by a pair of firmly crossed fingers, is an
invitation to disaster."
-John Clark, Ignition!
On 12/1/2015 1:48 PM, George Herbert wrote:
While I generally agree with Henry on monoprops, there are materialslike OTTO fuel, TATB, Fox-7, and Class 1.3 propellants where accidental
mass detonation is rare and energy density doesn't totally suck.
<hvanderbilt@xxxxxxxxxxxxxx> wrote:
We need stabler monoprops.
George William Herbert
Sent from my iPhone
On Dec 1, 2015, at 1:29 PM, Henry Vanderbilt
to have high performance is vanishingly unlikely to be reliably stable
I'm tempted to propose a rule: Any liquid monoprop energetic enough
under the violent conditions involved in flow through practical rocket
motor feed plumbing.
Nitrous/Fuel
On 12/1/2015 11:21 AM, Ken Doyle wrote:
That was me on Facebook mentioning that some success with
2012.mix was had in the gaseous phase.
I worked at Firestar in Mojave for 3 years, leaving in very early
isI'm pretty sure my NDA obligations have expired, and that Firestar
wavedefunct now.
The fundamental problem with use of a pre-mixed oxidizer/fuel in a
rocket motor is of course the issue of flashback, or a detonation
holding thetraveling upstream from the burning rocket motor to the tank
tubingmix. We did have success in developing Flashback Arrestors for the
gaseous phase. Those detonations usually didn't explode the SS
tests.on the way to the Arrestor, and diverting the detonation wave and
bursting relief parts kept away the big kabooms.
I setup and ran the tests of the arrestors, and the rocket motor
goingFor actual practical use in a flight motor, the higher density and
smaller plumbing sizes that come with liquid-phase operation were
andto be necessary. The ever-optomistic CEO/Chief Scientist/Pitchman
believed that the liquid phase of the mixes would be more stable
proved toeasier to arrest flashback than the gaseous phase. That hope
liquidnot be the case at all.
Although they may have made some progress after I left the company;
while I was there, we were never able to arrest flashback in the
withphase.
We did most of the work with Nitrous Oxide mixed with Ethylene or
Acetylene. We did a series of 14 meter Drop Tests of the mixes,
madethe Nitrous/Ethylene being much less prone to kerbleweys than the
Nitrous/Acetylene mixes. Although some attempt at subterfuge was
wereto make it appear that we had a secret ingredient to help with
stability, no ingredients other than Nitrous Oxide and the Fuel
firstactually used.
With the Nitrous/Acetylene stoichiometric ratio mix tested, the
had aDrop Test passed, but the second failed violently. The evil mix
lesstendency to explode at unexpected times; that is, in conditions
asevere than it had previously passed through. For instance, I did
in thecouple of slow heating tests which failed to explode at up to about
80C. Then, a test where it exploded at only 50C. The difference
intests was that the 50C explosion happened on a windy day, with some
slight agitation due to the wind moving the test apparatus.
Although the Nitrous/Ethylene mixes could pass some of the basic
handling safety tests, the arresting of flashback detonation waves
due tothe liquid phase was never solved while I was there.
In spite of highly negative handling safety experience with the
Nitrous/Acetylene mixes, a push persisted to make the stuff work,
mythe higher Isp number possible.
I was also chided about appearing to be afraid of the stuff, that
safecautious handling demeanor went against the company PR that it was
monopropellantto handle...
To sum up my opinion after working with Nitrous / Fuel
hardware.blends for 3 years;
1. They are too dangerous to be anywhere near humans or valuable
the2. The single tube/tank plumbing potential benefit is overcome by
bi-prop, isimpracticality and weight of feasible flashback arresting notions.
Use of Nitrous and a reasonable fuel such as Ethylene, as a
noneworth exploring.
It is conceivable that progress was made after I left Firestar, but
that.of my sources ever indicated such.
It is also conceivable that the ALASA / Boeing work with Nitrous /
Acetylene had no influence from the Firestar work, but I doubt
Ken Doyle