The tnt equivalency must have been determined by analysing the resultant
damage,barometric disturbances,etc. so the yield could be quantified.
NO2 gas is analogous to an ammonium nitrate 'detonation' like the
recent one in Beirut where a brown NO2 cloud was observed.
Seems like we end up back to this same topic, energetic oxidizers when LOx
really is all you need. The round vs square wheel invention cycle.
I know, they're exceptions and mine is nitric acid, MDA to be specific.
K
On Wed, Oct 21, 2020 at 10:06 AM Doug Jones <rocketplumber@xxxxxxxxx> wrote:
I ran out of the bunker when I heard the blast, and saw an orange mushroom
cloud rising high into the sky. Cold N2O vapor would hug the ground but I
don't recall whether I saw any fog at the Scaled site (I don't think any
other eyewitness accounts mentioned any fog). The ONLY way you get a
reddish, rising cloud from N2O is via decomposition and the formation of
NO2. The tank may have BLEVE'd after the injector blasted through it, but
the chamber simulator produced enough decomposition to produce a hot cloud
of gas with enough NO2 to be visible.
My best theory on the ignition is that the injector directed a stream of
fast-moving two-phase flow into a blind port such as a pressure
sensor, creating a resonant igniter accidentally. The resonant process can
take a few seconds to cause enough heating to start decomposition, which in
this case then propagated out of the sensor port and caused the high
density fog in the chamber to quickly deflagrate. The fog had the perfect
storm of lots of gas volume to carry the deflagration combined with fine
droplets to yield more energy. I don't have the calculations handy, but if
you isenthalpically throttle N2O liquid from 700 psi to 300 psi, then
decompose that fog, the pressure will rise to about 5000 psi. The hot gas
mix will inherently have a fraction of NO and NO2 in addition to N2 and O2.
If all the N2O had decomposed, I'm sure the toll would have been higher.
On Tue, Oct 20, 2020 at 6:42 PM Henry Spencer <hspencer@xxxxxxxxxxxxx>
wrote:
On Tue, 20 Oct 2020, ken mason wrote:
I wonder if any of these horror stories had any role in the fatal Scaled
nitrous blast of July 2007 which largely remains unsolved?
Although details have never been made public, it seems very likely that
the explosion started when nitrous contaminated with organics decomposed
(which, as Doug hinted, it does *much* more readily than pure nitrous)
and
overpressurized part of their test setup. The rest of it plausibly was
mostly a tank-burst BLEVE -- actual detonation of a tankful of N2O should
have been much more destructive.
There is ample evidence that Scaled had gotten too casual about nitrous,
so they probably weren't being cautious enough about materials and
cleaning. XCOR had some alarming minor incidents with nitrous earlier,
which stopped when they instituted LOX-class cleaning for all nitrous
plumbing.
Henry