Ray Gibbons responded to Tom Gehring:
On Sun, 23 Feb 1997, Tom Gehring wrote:
> Partial credit to a couple of the previous writers. But water neither
> displaces air nor increases oxygen content. For a given temperature and
> atmospheric pressure a cubic foot of air contains the same amount of
> oxygen no matter how much water it has in it. However, as an earlier
> Tom Gehring
> Chemical Engineer & '65 MGB owner
Tom,
I hesitate to dispute a Chemical Engineer, but what about Dalton's Law?
Each gas in a mixture exerts a pressure according to its own
concentration, independently of the other gases present. That is, each
<<<<<<<<<<<Snip>>>>>>>>>>>>>>
For a fixed pressure P, the partial pressure of oxygen would be less in
humid air than in dry air. I contend, then, that a cubic foot of dry
air
contains more O2 than a cubic foot of humid air, if the pressures are
the
same.
Ray
Ray Gibbons Dept. of Molecular Physiology & Biophysics
Univ. of Vermont College of Medicine, Burlington, VT
gibbons@northpole.med.uvm.edu (802) 656-8910
But what about the partial pressure of the gasoline that you are adding
to the system? Dry air contains about 21% oxygen, adding water vapor to
the air will decrese the overall percentage of oxygen but
it but will it not also lower the percentage of fuel that you are able
to get into the air? I think that the performance increases that are
seen have more to do with the density of the air entering the intake.
Lower temperature = more O2 per/liter. There was a discussion of air
boxes a while back for T series cars where the conventinal wisdom seems
to be the colder the air going into the intake the better....is the
reason for injecting water into the air cleaners more for being a swamp
cooler effect, cool the air to make it denser?
just my 2 cents
Paul Murch
University of Utah (5000' and low density air)
Chemistry (Organic Ph.D. in a month)
66b
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