On Fri, 31 Oct 2003 13:55:55 GMT, "Mark Browne"
wrote:

Rick and I just worked this out for water. In a race car tire that reaches
225 F to 250 F during normal operation, there *is* a phase change in water,
from liquid to vapor. The newly introduced water vapor can add a significant
component to the partial pressure composition of the tire. The only thing
left here is to determine how much liquid water might be found inside a tire
in different settings.

If there's any liquid water in the race tire/wheel at all, the tire
filler and wheel balancer should be fired. At the speed those tires
rotate, even a small amount of liquid water (say a few grams) would be
noticed as a vibration because the tire would be out of balance. It
doesn't get spread evenly around the inside of the tire.

Now in the temperature range of interest, operating tire temperatures, are
any of the materials you mention (Nitrogen, Argon, Oxygen) undergoing any
phase changes?
If not, do they show any appreciable deviation from the ideal gas properties
in the temperature range of interest?

It's pressure as well as temperature that would cause them to deviate
from ideal gas properties. And the pressures are not high enough.
Typically, you have to go above around 150 psi to notice any deviation
from the ideal gas laws. You have to go much higher than that for it to
have any appreciable effect.

As far as temperature is concerned, they deviate from ideal gas
properties at very low temperatures, temps near the phase change to
liquid. The higher the temp, the more ideal the gas behaves. If you're
only a few degress away from the phase change, you won't notice any
deviation from the ideal gas laws..

There is one other way a gas can deviate from the gas laws, and that's
at very small volumes. But the container must be so small that the
volume of the gas molecules themselves must be a significant portion of
the container. That is not the case with a tire.

If not, suck it up and move on.

Mark Browne
P. S. You would not be doing a Jax here, would you? That is, trying to
define the problem in such a narrow way as to give yourself a little wiggle
room. This is not necessarily a bad thing - some us miss toying with Jax!

At first, I thought he was Jax. But Jax at least had the courtesy to
confine the things he was wrong about to on-topic subjects. This idiot
is all over the spectrum.

Steve