On Dec 11, 2015, at 10:32 AM, Brian Feeney <alaiadesign@xxxxxxxxx> wrote:
Is it safe to use Hydrogen and separately oxygen as pressurizing gasses?
Set up:
- Gaseous Oxygen held in a separate low pressure vessel; about 300 psi.
- Prior to ignition a valve opens allowing O2 gas release into the LOX tank
to pressurize.
- LOX tank and pressure tank are equal volume with small ullage space
allocated in the LOX tank.
- pressure will decline by 50% through the burn based on the set up, that is
mission desirable to reduce thrust proportionately.
Hydrogen gas - same set up as above pressurizing the fuel supply feed side.
Dry nitrogen available to purge tanks, feed lines etc.
If repeat firings then only LOX and fuel lines would be purged up to the main
inlet valves, not the tanks which would be re-filled - some venting may be
necessary for refill even at these relatively low pressures?
Helium is the usual choice however, cost is high and given the description
above, I don't see the added safety benefits?
All comments, suggestions welcome.
Thank you,
Brian Feeney