In article ,
Roger Stokes wrote:
I googled recently that hydrogen will dissolve in hydrocarbons such as
decane when under pressure (and I can't find it again now!). It was unclear
to what percentage.

Unless it's fairly high pressure, I don't think you get very much of it
dissolved, alas.

I'm wondering if this has been looked at for pressurized tank use since
firstly, the hydrogen coming out of solution keeps the tank pressurized as
the propellant is used, so helium pressurization is not required, secondly
turbopumps are not required, and thirdly a decane/hydrogen mix would
presumably achieve a better ISP than RP1-type fuels on their own, with all
the advantages of a dense propellant.

Unfortunately, these are a bit contradictory -- unless you can get a *lot*
of hydrogen dissolved, if it comes out to pressurize the tank, it doesn't
go down into the engine to be burned.

Self-pressurizing systems are appealing, but often making them work
exactly right is harder than it looks. And they have the standard problem
of any pressure-fed system: heavy tanks.
--
MOST launched 30 June; first light, 29 July; 5arcsec | Henry Spencer
pointing, 10 Sept; first science, early Oct; all well. |