[PATCH 3/3] gas pressures: use an actual compressibility table for air

[Linus Torvalds]

On Feb 24, 2016 15:43, "Dirk Hohndel" <dirk at hohndel.org> wrote:
>
> But this bothers me. from 60 to 80 to 100 bar the z_factor goes UP!
> That just seems wrong. Maybe there's something in the physics that I don't
> get that makes this a magic range, but still... this at least needs an
> explanation.

I have no idea of what the physical explanation is, but if you look at the
compressibility graphs it turns out to not even be hugely unusual. To use a
highly technical term, they are some "funky shit".

Richard pointed to another table (on baue.org) of compressibility values
that had other gasses, and that had oxygen with even more of a dip (it's at
5% smaller volume than you'd expect at just 1300psi). So it compresses
*better* than you'd expect, more so than pure air.

I may be misusing and misunderstanding the Z factor, but yeah, I found it
surprising too.

        Linus
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