Density and boiling point change with pressure.
Dave
On 8/3/2016 12:05 PM, Zachary Martinez wrote:
Zachary Martinez
Aerospace Engineering | Missouri S&T
On Wed, Aug 3, 2016 at 12:33 AM, Henry Spencer <hspencer@xxxxxxxxxxxxx <mailto:hspencer@xxxxxxxxxxxxx>> wrote:
On Tue, 2 Aug 2016, Zachary Martinez wrote:
I have been curious about what can be used for pressurizing
gasses for liquid oxygen. The only two contenders I ever hear
about are helium and nitrogen... I would imagine that using
gox could be a solution. Obviously high pressure gox
introduces some hazards but other industries like scuba diving
use it successfully. Are hazards the only reason it is not
widely used.
No, the main snag with pressurizing LOX with GOX is the same as
for doing it with nitrogen: it readily dissolves in (more
precisely, condenses into) the LOX. This isn't quite as bad as
having nitrogen in the LOX, but it gives you a surface layer of
warm, low-density LOX and it complicates maintaining pressure.
I guess I'm kinda confused by this. How can you have warm low density lox? I always thought that either the LOX was liquid below its boiling point or it is at its boiling point and boiling off. Unless you get into using sub-cooled LOX I thought that in rocket applications all the LOX was all just sitting at its boiling point (the highest temperature for it to remain liquid) and the gas that boils off just bubbles up to the top out of the liquid. Can someone give a better explanation of this phenomenon please?
