[AR] Amateur Liquid TVC (was: Regarding Univerity solid rockets for cube-sat launch to orbit)
- From: Henry Vanderbilt <hvanderbilt@xxxxxxxxxxxxxx>
- To: arocket@xxxxxxxxxxxxx
- Date: Sat, 3 Mar 2018 18:19:58 -0700
On 3/3/2018 4:57 PM, John Schilling wrote:
On 3/3/2018 3:05 PM, Henry Vanderbilt wrote:
Duh! For a KISS liquid TVC demo, what do you think of nitrous for the
TVC fluid?
Henry
Nitrous should work, but I'm looking at an old DTIC report
<http://www.dtic.mil/dtic/tr/fulltext/u2/268731.pdf> that got decent
results from Freon. Looks like their application was for the old Subroc
system, whic as the name implies was meant to be used aboard submarines
and so wanted the safest possible liquids.
So, Mark I amateur system uses Freon, and if/when you need the extra
performance you start testing a Mark II using N2O. Carefully, because
it is an energetic oxidizer even if nominally benign at STP. If you get
that working safely and reliably, you can think about things like HAN.
Freon atmospheric release, alas, involves a lot more paperwork than it
used to.
For cheap easily-available fluids with similar
expands-a-lot-without-too-much-energy-input characteristics, there are
propane or butane. (Or one of the packaged propane-butane mixes that
were popular for a while as a cheap R-12 substitute in automobile air
conditioners. At least among the broke and adventurous, of which I was
one for some years.)
You could even run your main rocket oxidizer-rich to burn propane TVC
fluid... But we're wandering well away from "low-risk initial concept
test" there, never mind.
Henry
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